diff --git a/Documentation/rest-api-changes.txt b/Documentation/rest-api-changes.txt
index d83ef0e..0a203cc 100644
--- a/Documentation/rest-api-changes.txt
+++ b/Documentation/rest-api-changes.txt
@@ -2818,6 +2818,53 @@
   }
 ----
 
+[[check-submit-requirement]]
+=== Check Submit Requirement
+--
+'POST /changes/link:#change-id[\{change-id\}]/check.submit_requirement'
+--
+
+Tests a submit requirement and returns the result as a
+link:#submit-requirement-result-info[SubmitRequirementResultInfo]. The request
+body must contain a link:#submit-requirement-input[SubmitRequirementInput].
+
+Note that this endpoint does not modify the change resource.
+
+.Request
+----
+  POST /changes/myProject~master~I8473b95934b5732ac55d26311a706c9c2bde9940/check.submit_requirement HTTP/1.0
+  Content-Type: application/json; charset=UTF-8
+
+    {
+      "name": "Code-Review",
+      "submittability_expression": "label:Code-Review=+2"
+    }
+----
+
+As response a link:#submit-requirement-result-info[SubmitRequirementResultInfo]
+entity is returned that describes the submit requirement result.
+
+.Response
+----
+  HTTP/1.1 200 OK
+  Content-Disposition: attachment
+  Content-Type: application/json; charset=UTF-8
+
+  )]}'
+  {
+    "name": "Code-Review",
+    "status": "SATISFIED",
+    "submittability_expression_result": {
+      "expression": "label:Code-Review=+2",
+      "fulfilled": true,
+      "passingAtoms": [
+        "label:Code-Review=+2"
+      ]
+    },
+    "is_legacy": false
+  }
+----
+
 [[edit-endpoints]]
 == Change Edit Endpoints
 
@@ -7354,7 +7401,8 @@
 [[included-in-info]]
 === IncludedInInfo
 The `IncludedInInfo` entity contains information about the branches a
-change was merged into and tags it was tagged with.
+change was merged into and tags it was tagged with. The branch or tag
+must have 'refs/head/' or 'refs/tags/' prefix respectively.
 
 [options="header",cols="1,^1,5"]
 |=======================
@@ -8232,6 +8280,32 @@
 contains the list of predicates that are not fulfilled for the change.
 |===========================
 
+[[submit-requirement-input]]
+=== SubmitRequirementInput
+The `SubmitRequirementInput` entity describes a submit requirement.
+
+[options="header",cols="1,^1,5"]
+|===========================
+|Field Name      ||Description
+|`name`||
+The submit requirement name.
+|`description`|optional|
+Description of the submit requirement.
+|`applicability_expression`|optional|
+Query expression that can be evaluated on any change. If evaluated to true on a
+change, the submit requirement is then applicable for this change.
+If not specified, the submit requirement is applicable for all changes.
+|`submittability_expression`||
+Query expression that can be evaluated on any change. If evaluated to true on a
+change, the submit requirement is fulfilled and not blocking change submission.
+|`override_expression`|optional|
+Query expression that can be evaluated on any change. If evaluated to true on a
+change, the submit requirement is overridden and not blocking change submission.
+|`allow_override_in_child_projects`|optional|
+Whether this submit requirement can be overridden in child projects. Default is
+`true`.
+|===========================
+
 [[submit-requirement-result-info]]
 === SubmitRequirementResultInfo
 The `SubmitRequirementResultInfo` describes the result of evaluating a
@@ -8246,7 +8320,7 @@
 Description of the submit requirement.
 |`status`||
 Status describing the result of evaluating the submit requirement. The status
-is one of (`SATISFIED`, `UNSATISFIED`, `OVERRIDDEN`, `NOT_APPLICABLE`).
+is one of (`SATISFIED`, `UNSATISFIED`, `OVERRIDDEN`, `NOT_APPLICABLE`, `ERROR`).
 |`is_legacy`||
 If true, this submit requirement result was created from a legacy
 link:#submit-record[SubmitRecord]. Otherwise, it was created by evaluating a
diff --git a/java/com/google/gerrit/extensions/api/changes/ChangeApi.java b/java/com/google/gerrit/extensions/api/changes/ChangeApi.java
index 690ba4e..2224649 100644
--- a/java/com/google/gerrit/extensions/api/changes/ChangeApi.java
+++ b/java/com/google/gerrit/extensions/api/changes/ChangeApi.java
@@ -29,6 +29,8 @@
 import com.google.gerrit.extensions.common.PureRevertInfo;
 import com.google.gerrit.extensions.common.RevertSubmissionInfo;
 import com.google.gerrit.extensions.common.RobotCommentInfo;
+import com.google.gerrit.extensions.common.SubmitRequirementInput;
+import com.google.gerrit.extensions.common.SubmitRequirementResultInfo;
 import com.google.gerrit.extensions.common.SuggestedReviewerInfo;
 import com.google.gerrit.extensions.restapi.NotImplementedException;
 import com.google.gerrit.extensions.restapi.RestApiException;
@@ -425,6 +427,10 @@
 
   ChangeInfo check(FixInput fix) throws RestApiException;
 
+  /** Returns the result of evaluating the {@link SubmitRequirementInput} input on the change. */
+  SubmitRequirementResultInfo checkSubmitRequirement(SubmitRequirementInput input)
+      throws RestApiException;
+
   void index() throws RestApiException;
 
   /** Check if this change is a pure revert of the change stored in revertOf. */
@@ -761,6 +767,12 @@
     }
 
     @Override
+    public SubmitRequirementResultInfo checkSubmitRequirement(SubmitRequirementInput input)
+        throws RestApiException {
+      throw new NotImplementedException();
+    }
+
+    @Override
     public void index() throws RestApiException {
       throw new NotImplementedException();
     }
diff --git a/java/com/google/gerrit/extensions/common/SubmitRequirementInput.java b/java/com/google/gerrit/extensions/common/SubmitRequirementInput.java
new file mode 100644
index 0000000..96045d4
--- /dev/null
+++ b/java/com/google/gerrit/extensions/common/SubmitRequirementInput.java
@@ -0,0 +1,45 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.extensions.common;
+
+/** API Input describing a submit requirement entity. */
+public class SubmitRequirementInput {
+  /** Submit requirement name. */
+  public String name;
+
+  /** Submit requirement description. */
+  public String description;
+
+  /**
+   * Query expression that can be evaluated on any change. If evaluated to true on a change, the
+   * submit requirement is then applicable on this change.
+   */
+  public String applicabilityExpression;
+
+  /**
+   * Query expression that can be evaluated on any change. If evaluated to true on a change, the
+   * submit requirement is fulfilled and not blocking change submission.
+   */
+  public String submittabilityExpression;
+
+  /**
+   * Query expression that can be evaluated on any change. If evaluated to true on a change, the
+   * submit requirement is overridden and not blocking change submission.
+   */
+  public String overrideExpression;
+
+  /** Whether this submit requirement can be overridden in child projects. */
+  public Boolean allowOverrideInChildProjects;
+}
diff --git a/java/com/google/gerrit/extensions/common/SubmitRequirementResultInfo.java b/java/com/google/gerrit/extensions/common/SubmitRequirementResultInfo.java
index d17da0a..3d50f13 100644
--- a/java/com/google/gerrit/extensions/common/SubmitRequirementResultInfo.java
+++ b/java/com/google/gerrit/extensions/common/SubmitRequirementResultInfo.java
@@ -35,7 +35,13 @@
      * Submit requirement is not applicable for the change. Happens when {@code
      * applicabilityExpressionResult} is not fulfilled.
      */
-    NOT_APPLICABLE
+    NOT_APPLICABLE,
+
+    /**
+     * Any of the applicability, submittability or override expressions contain invalid syntax and
+     * are not parsable.
+     */
+    ERROR
   }
 
   /** Submit requirement name. */
diff --git a/java/com/google/gerrit/httpd/CacheBasedWebSession.java b/java/com/google/gerrit/httpd/CacheBasedWebSession.java
index 1605397..92e16ce 100644
--- a/java/com/google/gerrit/httpd/CacheBasedWebSession.java
+++ b/java/com/google/gerrit/httpd/CacheBasedWebSession.java
@@ -32,14 +32,12 @@
 import com.google.gerrit.server.account.externalids.ExternalId;
 import com.google.gerrit.server.config.AuthConfig;
 import com.google.inject.Provider;
-import com.google.inject.servlet.RequestScoped;
 import java.util.EnumSet;
 import javax.servlet.http.Cookie;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import org.eclipse.jgit.http.server.GitSmartHttpTools;
 
-@RequestScoped
 public abstract class CacheBasedWebSession extends WebSession {
   @VisibleForTesting public static final String ACCOUNT_COOKIE = "GerritAccount";
   protected static final long MAX_AGE_MINUTES = HOURS.toMinutes(12);
diff --git a/java/com/google/gerrit/server/api/changes/ChangeApiImpl.java b/java/com/google/gerrit/server/api/changes/ChangeApiImpl.java
index cbaf49e..a49061d 100644
--- a/java/com/google/gerrit/server/api/changes/ChangeApiImpl.java
+++ b/java/com/google/gerrit/server/api/changes/ChangeApiImpl.java
@@ -56,6 +56,8 @@
 import com.google.gerrit.extensions.common.PureRevertInfo;
 import com.google.gerrit.extensions.common.RevertSubmissionInfo;
 import com.google.gerrit.extensions.common.RobotCommentInfo;
+import com.google.gerrit.extensions.common.SubmitRequirementInput;
+import com.google.gerrit.extensions.common.SubmitRequirementResultInfo;
 import com.google.gerrit.extensions.common.SuggestedReviewerInfo;
 import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.extensions.restapi.BadRequestException;
@@ -74,6 +76,7 @@
 import com.google.gerrit.server.restapi.change.ChangeIncludedIn;
 import com.google.gerrit.server.restapi.change.ChangeMessages;
 import com.google.gerrit.server.restapi.change.Check;
+import com.google.gerrit.server.restapi.change.CheckSubmitRequirement;
 import com.google.gerrit.server.restapi.change.CreateMergePatchSet;
 import com.google.gerrit.server.restapi.change.DeleteAssignee;
 import com.google.gerrit.server.restapi.change.DeleteChange;
@@ -164,6 +167,7 @@
   private final Provider<ListChangeDrafts> listDraftsProvider;
   private final ChangeEditApiImpl.Factory changeEditApi;
   private final Check check;
+  private final CheckSubmitRequirement checkSubmitRequirement;
   private final Index index;
   private final Move move;
   private final PostPrivate postPrivate;
@@ -218,6 +222,7 @@
       Provider<ListChangeDrafts> listDraftsProvider,
       ChangeEditApiImpl.Factory changeEditApi,
       Check check,
+      CheckSubmitRequirement checkSubmitRequirement,
       Index index,
       Move move,
       PostPrivate postPrivate,
@@ -270,6 +275,7 @@
     this.listDraftsProvider = listDraftsProvider;
     this.changeEditApi = changeEditApi;
     this.check = check;
+    this.checkSubmitRequirement = checkSubmitRequirement;
     this.index = index;
     this.move = move;
     this.postPrivate = postPrivate;
@@ -708,6 +714,16 @@
   }
 
   @Override
+  public SubmitRequirementResultInfo checkSubmitRequirement(SubmitRequirementInput input)
+      throws RestApiException {
+    try {
+      return checkSubmitRequirement.apply(change, input).value();
+    } catch (Exception e) {
+      throw asRestApiException("Cannot check submit requirement", e);
+    }
+  }
+
+  @Override
   public void index() throws RestApiException {
     try {
       index.apply(change, new Input());
diff --git a/java/com/google/gerrit/server/cache/PerThreadCache.java b/java/com/google/gerrit/server/cache/PerThreadCache.java
index b4f79d1..ef00b80 100644
--- a/java/com/google/gerrit/server/cache/PerThreadCache.java
+++ b/java/com/google/gerrit/server/cache/PerThreadCache.java
@@ -68,7 +68,7 @@
 
     /**
      * Returns a key based on the value's class and an identifier that uniquely identify the value.
-     * The identifier needs to implement {@code equals()} and {@hashCode()}.
+     * The identifier needs to implement {@code equals()} and {@code hashCode()}.
      */
     public static <T> Key<T> create(Class<T> clazz, Object identifier) {
       return new Key<>(clazz, ImmutableList.of(identifier));
@@ -76,7 +76,7 @@
 
     /**
      * Returns a key based on the value's class and a set of identifiers that uniquely identify the
-     * value. Identifiers need to implement {@code equals()} and {@hashCode()}.
+     * value. Identifiers need to implement {@code equals()} and {@code hashCode()}.
      */
     public static <T> Key<T> create(Class<T> clazz, Object... identifiers) {
       return new Key<>(clazz, ImmutableList.copyOf(identifiers));
diff --git a/java/com/google/gerrit/server/change/ChangeJson.java b/java/com/google/gerrit/server/change/ChangeJson.java
index db25dc7..9a94d93 100644
--- a/java/com/google/gerrit/server/change/ChangeJson.java
+++ b/java/com/google/gerrit/server/change/ChangeJson.java
@@ -61,8 +61,6 @@
 import com.google.gerrit.entities.SubmitRecord;
 import com.google.gerrit.entities.SubmitRecord.Status;
 import com.google.gerrit.entities.SubmitRequirement;
-import com.google.gerrit.entities.SubmitRequirementExpression;
-import com.google.gerrit.entities.SubmitRequirementExpressionResult;
 import com.google.gerrit.entities.SubmitRequirementResult;
 import com.google.gerrit.entities.SubmitTypeRecord;
 import com.google.gerrit.exceptions.StorageException;
@@ -80,7 +78,6 @@
 import com.google.gerrit.extensions.common.ReviewerUpdateInfo;
 import com.google.gerrit.extensions.common.RevisionInfo;
 import com.google.gerrit.extensions.common.SubmitRecordInfo;
-import com.google.gerrit.extensions.common.SubmitRequirementExpressionInfo;
 import com.google.gerrit.extensions.common.SubmitRequirementResultInfo;
 import com.google.gerrit.extensions.common.TrackingIdInfo;
 import com.google.gerrit.extensions.restapi.Url;
@@ -378,11 +375,11 @@
     return submitRecordInfos;
   }
 
-  private static Collection<SubmitRequirementResultInfo> submitRequirementsFor(ChangeData cd) {
+  private Collection<SubmitRequirementResultInfo> submitRequirementsFor(ChangeData cd) {
     Collection<SubmitRequirementResultInfo> reqInfos = new ArrayList<>();
     Map<SubmitRequirement, SubmitRequirementResult> requirements = cd.submitRequirements();
     for (Map.Entry<SubmitRequirement, SubmitRequirementResult> entry : requirements.entrySet()) {
-      reqInfos.add(submitRequirementToInfo(entry.getKey(), entry.getValue()));
+      reqInfos.add(SubmitRequirementsJson.toInfo(entry.getKey(), entry.getValue()));
     }
     return reqInfos;
   }
@@ -420,39 +417,6 @@
     return info;
   }
 
-  private static SubmitRequirementResultInfo submitRequirementToInfo(
-      SubmitRequirement req, SubmitRequirementResult result) {
-    SubmitRequirementResultInfo info = new SubmitRequirementResultInfo();
-    info.name = req.name();
-    info.description = req.description().orElse(null);
-    if (req.applicabilityExpression().isPresent()) {
-      info.applicabilityExpressionResult =
-          submitRequirementExpressionToInfo(
-              req.applicabilityExpression().get(), result.applicabilityExpressionResult().get());
-    }
-    if (req.overrideExpression().isPresent()) {
-      info.overrideExpressionResult =
-          submitRequirementExpressionToInfo(
-              req.overrideExpression().get(), result.overrideExpressionResult().get());
-    }
-    info.submittabilityExpressionResult =
-        submitRequirementExpressionToInfo(
-            req.submittabilityExpression(), result.submittabilityExpressionResult());
-    info.status = SubmitRequirementResultInfo.Status.valueOf(result.status().toString());
-    info.isLegacy = result.legacy();
-    return info;
-  }
-
-  private static SubmitRequirementExpressionInfo submitRequirementExpressionToInfo(
-      SubmitRequirementExpression expression, SubmitRequirementExpressionResult result) {
-    SubmitRequirementExpressionInfo info = new SubmitRequirementExpressionInfo();
-    info.expression = expression.expressionString();
-    info.fulfilled = result.status().equals(SubmitRequirementExpressionResult.Status.PASS);
-    info.passingAtoms = result.passingAtoms();
-    info.failingAtoms = result.failingAtoms();
-    return info;
-  }
-
   private static void finish(ChangeInfo info) {
     info.id =
         Joiner.on('~')
diff --git a/java/com/google/gerrit/server/change/SubmitRequirementsJson.java b/java/com/google/gerrit/server/change/SubmitRequirementsJson.java
new file mode 100644
index 0000000..ebb0790
--- /dev/null
+++ b/java/com/google/gerrit/server/change/SubmitRequirementsJson.java
@@ -0,0 +1,63 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.change;
+
+import com.google.gerrit.entities.SubmitRequirement;
+import com.google.gerrit.entities.SubmitRequirementExpression;
+import com.google.gerrit.entities.SubmitRequirementExpressionResult;
+import com.google.gerrit.entities.SubmitRequirementResult;
+import com.google.gerrit.extensions.common.SubmitRequirementExpressionInfo;
+import com.google.gerrit.extensions.common.SubmitRequirementResultInfo;
+
+/**
+ * Produces submit requirements related entities like {@link SubmitRequirementResultInfo}s, which
+ * are serialized to JSON afterwards.
+ */
+public class SubmitRequirementsJson {
+  private SubmitRequirementsJson() {}
+
+  public static SubmitRequirementResultInfo toInfo(
+      SubmitRequirement req, SubmitRequirementResult result) {
+    SubmitRequirementResultInfo info = new SubmitRequirementResultInfo();
+    info.name = req.name();
+    info.description = req.description().orElse(null);
+    if (req.applicabilityExpression().isPresent()) {
+      info.applicabilityExpressionResult =
+          submitRequirementExpressionToInfo(
+              req.applicabilityExpression().get(), result.applicabilityExpressionResult().get());
+    }
+    if (req.overrideExpression().isPresent()) {
+      info.overrideExpressionResult =
+          submitRequirementExpressionToInfo(
+              req.overrideExpression().get(), result.overrideExpressionResult().get());
+    }
+    info.submittabilityExpressionResult =
+        submitRequirementExpressionToInfo(
+            req.submittabilityExpression(), result.submittabilityExpressionResult());
+    info.status = SubmitRequirementResultInfo.Status.valueOf(result.status().toString());
+    info.isLegacy = result.legacy();
+    return info;
+  }
+
+  private static SubmitRequirementExpressionInfo submitRequirementExpressionToInfo(
+      SubmitRequirementExpression expression, SubmitRequirementExpressionResult result) {
+    SubmitRequirementExpressionInfo info = new SubmitRequirementExpressionInfo();
+    info.expression = expression.expressionString();
+    info.fulfilled = result.status().equals(SubmitRequirementExpressionResult.Status.PASS);
+    info.passingAtoms = result.passingAtoms();
+    info.failingAtoms = result.failingAtoms();
+    return info;
+  }
+}
diff --git a/java/com/google/gerrit/server/events/EventFactory.java b/java/com/google/gerrit/server/events/EventFactory.java
index 951167a..a7fea3c 100644
--- a/java/com/google/gerrit/server/events/EventFactory.java
+++ b/java/com/google/gerrit/server/events/EventFactory.java
@@ -400,7 +400,7 @@
     try {
       Map<String, FileDiffOutput> modifiedFiles =
           diffOperations.listModifiedFilesAgainstParent(
-              change.getProject(), patchSet.commitId(), /* parent= */ 0);
+              change.getProject(), patchSet.commitId(), /* parentNum= */ 0);
 
       for (FileDiffOutput diff : modifiedFiles.values()) {
         if (patchSetAttribute.files == null) {
@@ -457,7 +457,7 @@
 
       Map<String, FileDiffOutput> modifiedFiles =
           diffOperations.listModifiedFilesAgainstParent(
-              change.getProject(), patchSet.commitId(), /* parent= */ 0);
+              change.getProject(), patchSet.commitId(), /* parentNum= */ 0);
       for (FileDiffOutput fileDiff : modifiedFiles.values()) {
         p.sizeDeletions += fileDiff.deletions();
         p.sizeInsertions += fileDiff.insertions();
diff --git a/java/com/google/gerrit/server/git/validators/ValidationMessage.java b/java/com/google/gerrit/server/git/validators/ValidationMessage.java
index b5d7eb1..c743bbc 100644
--- a/java/com/google/gerrit/server/git/validators/ValidationMessage.java
+++ b/java/com/google/gerrit/server/git/validators/ValidationMessage.java
@@ -68,7 +68,8 @@
   }
 
   /**
-   * Returns {@true} if this message is an error. Used to decide if the operation should be aborted.
+   * Returns {@code true} if this message is an error. Used to decide if the operation should be
+   * aborted.
    */
   public boolean isError() {
     return type == Type.FATAL || type == Type.ERROR;
diff --git a/java/com/google/gerrit/server/restapi/change/CheckSubmitRequirement.java b/java/com/google/gerrit/server/restapi/change/CheckSubmitRequirement.java
new file mode 100644
index 0000000..55b234c
--- /dev/null
+++ b/java/com/google/gerrit/server/restapi/change/CheckSubmitRequirement.java
@@ -0,0 +1,79 @@
+// Copyright (C) 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.restapi.change;
+
+import com.google.gerrit.entities.SubmitRequirement;
+import com.google.gerrit.entities.SubmitRequirementExpression;
+import com.google.gerrit.entities.SubmitRequirementResult;
+import com.google.gerrit.extensions.common.SubmitRequirementInput;
+import com.google.gerrit.extensions.common.SubmitRequirementResultInfo;
+import com.google.gerrit.extensions.restapi.BadRequestException;
+import com.google.gerrit.extensions.restapi.Response;
+import com.google.gerrit.extensions.restapi.RestModifyView;
+import com.google.gerrit.server.change.ChangeResource;
+import com.google.gerrit.server.change.SubmitRequirementsJson;
+import com.google.gerrit.server.project.SubmitRequirementsEvaluator;
+import com.google.inject.Inject;
+import java.util.Optional;
+
+/**
+ * A rest view to evaluate (test) a {@link com.google.gerrit.entities.SubmitRequirement} on a given
+ * change.
+ *
+ * <p>TODO(ghareeb): Can this class be made singleton?
+ */
+public class CheckSubmitRequirement
+    implements RestModifyView<ChangeResource, SubmitRequirementInput> {
+  private final SubmitRequirementsEvaluator evaluator;
+
+  @Inject
+  public CheckSubmitRequirement(SubmitRequirementsEvaluator evaluator) {
+    this.evaluator = evaluator;
+  }
+
+  @Override
+  public Response<SubmitRequirementResultInfo> apply(
+      ChangeResource resource, SubmitRequirementInput input) throws BadRequestException {
+    SubmitRequirement requirement = createSubmitRequirement(input);
+    SubmitRequirementResult res =
+        evaluator.evaluateRequirement(requirement, resource.getChangeData());
+    return Response.ok(SubmitRequirementsJson.toInfo(requirement, res));
+  }
+
+  private SubmitRequirement createSubmitRequirement(SubmitRequirementInput input)
+      throws BadRequestException {
+    validateSubmitRequirementInput(input);
+    return SubmitRequirement.builder()
+        .setName(input.name)
+        .setDescription(Optional.ofNullable(input.description))
+        .setApplicabilityExpression(SubmitRequirementExpression.of(input.applicabilityExpression))
+        .setSubmittabilityExpression(
+            SubmitRequirementExpression.create(input.submittabilityExpression))
+        .setOverrideExpression(SubmitRequirementExpression.of(input.overrideExpression))
+        .setAllowOverrideInChildProjects(
+            input.allowOverrideInChildProjects == null ? true : input.allowOverrideInChildProjects)
+        .build();
+  }
+
+  private void validateSubmitRequirementInput(SubmitRequirementInput input)
+      throws BadRequestException {
+    if (input.name == null) {
+      throw new BadRequestException("Field 'name' is missing from input.");
+    }
+    if (input.submittabilityExpression == null) {
+      throw new BadRequestException("Field 'submittability_expression' is missing from input.");
+    }
+  }
+}
diff --git a/java/com/google/gerrit/server/restapi/change/Module.java b/java/com/google/gerrit/server/restapi/change/Module.java
index 000a17e..4d955fb 100644
--- a/java/com/google/gerrit/server/restapi/change/Module.java
+++ b/java/com/google/gerrit/server/restapi/change/Module.java
@@ -123,6 +123,7 @@
     post(CHANGE_KIND, "wip").to(SetWorkInProgress.class);
     post(CHANGE_KIND, "ready").to(SetReadyForReview.class);
     put(CHANGE_KIND, "message").to(PutMessage.class);
+    post(CHANGE_KIND, "check.submit_requirement").to(CheckSubmitRequirement.class);
 
     get(CHANGE_KIND, "suggest_reviewers").to(SuggestChangeReviewers.class);
     child(CHANGE_KIND, "reviewers").to(Reviewers.class);
diff --git a/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java b/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
index 52202d7..e657c89 100644
--- a/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/change/ChangeIT.java
@@ -153,6 +153,7 @@
 import com.google.gerrit.extensions.common.LegacySubmitRequirementInfo;
 import com.google.gerrit.extensions.common.RevisionInfo;
 import com.google.gerrit.extensions.common.SubmitRecordInfo;
+import com.google.gerrit.extensions.common.SubmitRequirementInput;
 import com.google.gerrit.extensions.common.SubmitRequirementResultInfo;
 import com.google.gerrit.extensions.common.SubmitRequirementResultInfo.Status;
 import com.google.gerrit.extensions.common.TrackingIdInfo;
@@ -4074,6 +4075,90 @@
   }
 
   @Test
+  public void checkSubmitRequirement_satisfied() throws Exception {
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+
+    SubmitRequirementInput in =
+        createSubmitRequirementInput(
+            "Code-Review", /* submittabilityExpression= */ "label:Code-Review=+2");
+
+    SubmitRequirementResultInfo result = gApi.changes().id(changeId).checkSubmitRequirement(in);
+    assertThat(result.status).isEqualTo(SubmitRequirementResultInfo.Status.UNSATISFIED);
+
+    voteLabel(changeId, "Code-Review", 2);
+    result = gApi.changes().id(changeId).checkSubmitRequirement(in);
+    assertThat(result.status).isEqualTo(SubmitRequirementResultInfo.Status.SATISFIED);
+  }
+
+  @Test
+  public void checkSubmitRequirement_notApplicable() throws Exception {
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+
+    SubmitRequirementInput in =
+        createSubmitRequirementInput(
+            "Code-Review",
+            /* applicableIf= */ "branch:non-existent",
+            /* submittableIf= */ "label:Code-Review=+2",
+            /* overrideIf= */ null);
+
+    SubmitRequirementResultInfo result = gApi.changes().id(changeId).checkSubmitRequirement(in);
+    assertThat(result.status).isEqualTo(SubmitRequirementResultInfo.Status.NOT_APPLICABLE);
+
+    voteLabel(changeId, "Code-Review", 2);
+    result = gApi.changes().id(changeId).checkSubmitRequirement(in);
+    assertThat(result.status).isEqualTo(SubmitRequirementResultInfo.Status.NOT_APPLICABLE);
+  }
+
+  @Test
+  public void checkSubmitRequirement_overridden() throws Exception {
+    configLabel("Override-Label", LabelFunction.NO_OP); // label function has no effect
+    projectOperations
+        .project(project)
+        .forUpdate()
+        .add(
+            allowLabel("Override-Label")
+                .ref("refs/heads/master")
+                .group(REGISTERED_USERS)
+                .range(-1, 1))
+        .update();
+
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+
+    SubmitRequirementInput in =
+        createSubmitRequirementInput(
+            "Code-Review",
+            /* applicableIf= */ null,
+            /* submittableIf= */ "label:Code-Review=+2",
+            /* overrideIf= */ "label:Override-Label=+1");
+
+    SubmitRequirementResultInfo result = gApi.changes().id(changeId).checkSubmitRequirement(in);
+    assertThat(result.status).isEqualTo(SubmitRequirementResultInfo.Status.UNSATISFIED);
+
+    voteLabel(changeId, "Code-Review", 2);
+    result = gApi.changes().id(changeId).checkSubmitRequirement(in);
+    assertThat(result.status).isEqualTo(SubmitRequirementResultInfo.Status.SATISFIED);
+
+    voteLabel(changeId, "Override-Label", 1);
+    result = gApi.changes().id(changeId).checkSubmitRequirement(in);
+    assertThat(result.status).isEqualTo(SubmitRequirementResultInfo.Status.OVERRIDDEN);
+  }
+
+  @Test
+  public void checkSubmitRequirement_error() throws Exception {
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+
+    SubmitRequirementInput in =
+        createSubmitRequirementInput("Code-Review", /* submittabilityExpression= */ "!!!");
+
+    SubmitRequirementResultInfo result = gApi.changes().id(changeId).checkSubmitRequirement(in);
+    assertThat(result.status).isEqualTo(SubmitRequirementResultInfo.Status.ERROR);
+  }
+
+  @Test
   public void submitRequirement_withLabelEqualsMax() throws Exception {
     configSubmitRequirement(
         project,
@@ -5393,4 +5478,22 @@
       return Optional.of(record);
     }
   }
+
+  private static SubmitRequirementInput createSubmitRequirementInput(
+      String name, String submittabilityExpression) {
+    SubmitRequirementInput input = new SubmitRequirementInput();
+    input.name = name;
+    input.submittabilityExpression = submittabilityExpression;
+    return input;
+  }
+
+  private static SubmitRequirementInput createSubmitRequirementInput(
+      String name, String applicableIf, String submittableIf, String overrideIf) {
+    SubmitRequirementInput input = new SubmitRequirementInput();
+    input.name = name;
+    input.applicabilityExpression = applicableIf;
+    input.submittabilityExpression = submittableIf;
+    input.overrideExpression = overrideIf;
+    return input;
+  }
 }
diff --git a/javatests/com/google/gerrit/acceptance/server/query/ApprovalQueryIT.java b/javatests/com/google/gerrit/acceptance/server/query/ApprovalQueryIT.java
index b4d9558..537c7d8 100644
--- a/javatests/com/google/gerrit/acceptance/server/query/ApprovalQueryIT.java
+++ b/javatests/com/google/gerrit/acceptance/server/query/ApprovalQueryIT.java
@@ -68,8 +68,7 @@
   public void changeKindPredicate_noCodeChange() throws Exception {
     String change = changeKindCreator.createChange(ChangeKind.NO_CODE_CHANGE, testRepo, admin);
     changeKindCreator.updateChange(change, ChangeKind.NO_CODE_CHANGE, testRepo, admin, project);
-    PatchSet.Id ps1 =
-        PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* psId= */ 1);
+    PatchSet.Id ps1 = PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* id= */ 1);
     assertTrue(
         queryBuilder
             .parse("changekind:no-code-change")
@@ -77,8 +76,7 @@
             .match(contextForCodeReviewLabel(/* value= */ -2, ps1, admin.id())));
 
     changeKindCreator.updateChange(change, ChangeKind.TRIVIAL_REBASE, testRepo, admin, project);
-    PatchSet.Id ps2 =
-        PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* psId= */ 2);
+    PatchSet.Id ps2 = PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* id= */ 2);
     assertFalse(
         queryBuilder
             .parse("changekind:no-code-change")
@@ -90,8 +88,7 @@
   public void changeKindPredicate_trivialRebase() throws Exception {
     String change = changeKindCreator.createChange(ChangeKind.TRIVIAL_REBASE, testRepo, admin);
     changeKindCreator.updateChange(change, ChangeKind.TRIVIAL_REBASE, testRepo, admin, project);
-    PatchSet.Id ps1 =
-        PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* psId= */ 1);
+    PatchSet.Id ps1 = PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* id= */ 1);
     assertTrue(
         queryBuilder
             .parse("changekind:trivial-rebase")
@@ -99,8 +96,7 @@
             .match(contextForCodeReviewLabel(/* value= */ -2, ps1, admin.id())));
 
     changeKindCreator.updateChange(change, ChangeKind.REWORK, testRepo, admin, project);
-    PatchSet.Id ps2 =
-        PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* psId= */ 2);
+    PatchSet.Id ps2 = PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* id= */ 2);
     assertFalse(
         queryBuilder
             .parse("changekind:trivial-rebase")
@@ -112,8 +108,7 @@
   public void changeKindPredicate_reworkAndNotRework() throws Exception {
     String change = changeKindCreator.createChange(ChangeKind.REWORK, testRepo, admin);
     changeKindCreator.updateChange(change, ChangeKind.REWORK, testRepo, admin, project);
-    PatchSet.Id ps1 =
-        PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* psId= */ 1);
+    PatchSet.Id ps1 = PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* id= */ 1);
     assertTrue(
         queryBuilder
             .parse("changekind:rework")
@@ -121,8 +116,7 @@
             .match(contextForCodeReviewLabel(/* value= */ -2, ps1, admin.id())));
 
     changeKindCreator.updateChange(change, ChangeKind.REWORK, testRepo, admin, project);
-    PatchSet.Id ps2 =
-        PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* psId= */ 2);
+    PatchSet.Id ps2 = PatchSet.id(Change.id(gApi.changes().id(change).get()._number), /* id= */ 2);
     assertFalse(
         queryBuilder
             .parse("-changekind:rework")
@@ -150,7 +144,7 @@
             .match(
                 contextForCodeReviewLabel(
                     /* value= */ 2,
-                    PatchSet.id(pushResult.getChange().getId(), /* psId= */ 1),
+                    PatchSet.id(pushResult.getChange().getId(), /* id= */ 1),
                     admin.id())));
     // can not copy approval from patchset 2 -> 3
     assertFalse(
@@ -160,7 +154,7 @@
             .match(
                 contextForCodeReviewLabel(
                     /* value= */ 2,
-                    PatchSet.id(pushResult.getChange().getId(), /* psId= */ 2),
+                    PatchSet.id(pushResult.getChange().getId(), /* id= */ 2),
                     admin.id())));
   }
 
@@ -179,7 +173,7 @@
             .match(
                 contextForCodeReviewLabel(
                     /* value= */ 2,
-                    PatchSet.id(pushResult.getChange().getId(), /* psId= */ 1),
+                    PatchSet.id(pushResult.getChange().getId(), /* id= */ 1),
                     admin.id())));
     // can not copy approval from patchset 2 -> 3
     assertFalse(
@@ -189,7 +183,7 @@
             .match(
                 contextForCodeReviewLabel(
                     /* value= */ 2,
-                    PatchSet.id(pushResult.getChange().getId(), /* psId= */ 2),
+                    PatchSet.id(pushResult.getChange().getId(), /* id= */ 2),
                     user.id())));
   }
 
@@ -219,7 +213,7 @@
             .asMatchable()
             .match(
                 contextForCodeReviewLabel(
-                    /* value= */ 2, PatchSet.id(changeId, /* psId= */ 1), admin.id())));
+                    /* value= */ 2, PatchSet.id(changeId, /* id= */ 1), admin.id())));
     changeOperations.change(changeId).newPatchset().file("file").delete().create();
 
     // can not copy approval from patch-set 2 -> 3
@@ -229,7 +223,7 @@
             .asMatchable()
             .match(
                 contextForCodeReviewLabel(
-                    /* value= */ 2, PatchSet.id(changeId, /* psId= */ 2), admin.id())));
+                    /* value= */ 2, PatchSet.id(changeId, /* id= */ 2), admin.id())));
   }
 
   @Test
diff --git a/polygerrit-ui/app/elements/change/gr-submit-requirement-hovercard/gr-submit-requirement-hovercard.ts b/polygerrit-ui/app/elements/change/gr-submit-requirement-hovercard/gr-submit-requirement-hovercard.ts
index d90d173..5feb1ae 100644
--- a/polygerrit-ui/app/elements/change/gr-submit-requirement-hovercard/gr-submit-requirement-hovercard.ts
+++ b/polygerrit-ui/app/elements/change/gr-submit-requirement-hovercard/gr-submit-requirement-hovercard.ts
@@ -16,7 +16,6 @@
  */
 import '../../shared/gr-button/gr-button';
 import '../../shared/gr-label-info/gr-label-info';
-import '../../shared/gr-limited-text/gr-limited-text';
 import {customElement, property} from 'lit/decorators';
 import {
   AccountInfo,
@@ -37,7 +36,7 @@
 const base = HovercardMixin(LitElement);
 
 @customElement('gr-submit-requirement-hovercard')
-export class GrHovercardRun extends base {
+export class GrSubmitRequirementHovercard extends base {
   @property({type: Object})
   requirement?: SubmitRequirementResultInfo;
 
@@ -261,6 +260,6 @@
 
 declare global {
   interface HTMLElementTagNameMap {
-    'gr-submit-requirement-hovercard': GrHovercardRun;
+    'gr-submit-requirement-hovercard': GrSubmitRequirementHovercard;
   }
 }
diff --git a/polygerrit-ui/app/elements/change/gr-submit-requirements/gr-submit-requirements.ts b/polygerrit-ui/app/elements/change/gr-submit-requirements/gr-submit-requirements.ts
index 004d594..40d80bd 100644
--- a/polygerrit-ui/app/elements/change/gr-submit-requirements/gr-submit-requirements.ts
+++ b/polygerrit-ui/app/elements/change/gr-submit-requirements/gr-submit-requirements.ts
@@ -14,7 +14,9 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+import '../../shared/gr-label-info/gr-label-info';
 import '../gr-submit-requirement-hovercard/gr-submit-requirement-hovercard';
+import '../gr-trigger-vote-hovercard/gr-trigger-vote-hovercard';
 import {LitElement, css, html} from 'lit';
 import {customElement, property, state} from 'lit/decorators';
 import {ParsedChangeInfo} from '../../../types/types';
@@ -271,6 +273,9 @@
             html`<gr-trigger-vote
               .label="${label}"
               .labelInfo="${labels[label]}"
+              .change="${this.change}"
+              .account="${this.account}"
+              .mutable="${this.mutable ?? false}"
             ></gr-trigger-vote>`
         )}
       </section>`;
@@ -285,6 +290,15 @@
   @property({type: Object})
   labelInfo?: LabelInfo;
 
+  @property({type: Object})
+  change?: ParsedChangeInfo;
+
+  @property({type: Object})
+  account?: AccountInfo;
+
+  @property({type: Boolean})
+  mutable?: boolean;
+
   static override get styles() {
     return css`
       :host {
@@ -309,6 +323,10 @@
         --gr-vote-chip-width: 14px;
         --gr-vote-chip-height: 14px;
         margin-right: 0px;
+        margin-left: var(--spacing-xs);
+      }
+      gr-vote-chip:first-of-type {
+        margin-left: 0px;
       }
     `;
   }
@@ -317,6 +335,17 @@
     if (!this.labelInfo) return;
     return html`
       <div class="container">
+        <gr-trigger-vote-hovercard .labelName=${this.label}>
+          <gr-label-info
+            slot="label-info"
+            .change=${this.change}
+            .account=${this.account}
+            .mutable=${this.mutable}
+            .label=${this.label}
+            .labelInfo=${this.labelInfo}
+            .showAllReviewers=${false}
+          ></gr-label-info>
+        </gr-trigger-vote-hovercard>
         <span class="label">${this.label}</span>
         ${this.renderVotes()}
       </div>
diff --git a/polygerrit-ui/app/elements/change/gr-trigger-vote-hovercard/gr-trigger-vote-hovercard.ts b/polygerrit-ui/app/elements/change/gr-trigger-vote-hovercard/gr-trigger-vote-hovercard.ts
new file mode 100644
index 0000000..552cc69
--- /dev/null
+++ b/polygerrit-ui/app/elements/change/gr-trigger-vote-hovercard/gr-trigger-vote-hovercard.ts
@@ -0,0 +1,94 @@
+/**
+ * @license
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import {customElement, property} from 'lit/decorators';
+import {css, html, LitElement} from 'lit';
+import {HovercardMixin} from '../../../mixins/hovercard-mixin/hovercard-mixin';
+import {fontStyles} from '../../../styles/gr-font-styles';
+
+// This avoids JSC_DYNAMIC_EXTENDS_WITHOUT_JSDOC closure compiler error.
+const base = HovercardMixin(LitElement);
+
+@customElement('gr-trigger-vote-hovercard')
+export class GrTriggerVoteHovercard extends base {
+  @property()
+  labelName?: string;
+
+  static override get styles() {
+    return [
+      fontStyles,
+      base.styles || [],
+      css`
+        #container {
+          min-width: 300px;
+          max-width: 300px;
+          padding: var(--spacing-xl) 0 var(--spacing-m) 0;
+        }
+        .row {
+          display: flex;
+        }
+        .title {
+          color: var(--deemphasized-text-color);
+          margin-right: var(--spacing-m);
+        }
+        div.section {
+          margin: 0 var(--spacing-xl) var(--spacing-m) var(--spacing-xl);
+          display: flex;
+          align-items: flex-start;
+        }
+        div.sectionIcon {
+          flex: 0 0 30px;
+        }
+        div.sectionIcon iron-icon {
+          position: relative;
+          width: 20px;
+          height: 20px;
+        }
+      `,
+    ];
+  }
+
+  override render() {
+    return html` <div id="container" role="tooltip" tabindex="-1">
+      <div class="section">
+        <div class="sectionContent">
+          <h3 class="name heading-3">
+            <span>${this.labelName}</span>
+          </h3>
+        </div>
+      </div>
+      <div class="section">
+        <div class="sectionIcon">
+          <iron-icon class="small" icon="gr-icons:info-outline"></iron-icon>
+        </div>
+        <div class="sectionContent">
+          <div class="row">
+            <div class="title">Status</div>
+            <div>
+              <slot name="label-info"></slot>
+            </div>
+          </div>
+        </div>
+      </div>
+    </div>`;
+  }
+}
+
+declare global {
+  interface HTMLElementTagNameMap {
+    'gr-trigger-vote-hovercard': GrTriggerVoteHovercard;
+  }
+}
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector.ts b/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector.ts
index a7702d1..b47c51c 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector.ts
@@ -46,7 +46,7 @@
   @property({type: Boolean})
   showTooltipBelow = false;
 
-  private readonly restApiService = appContext.restApiService;
+  private readonly userService = appContext.userService;
 
   override connectedCallback() {
     super.connectedCallback();
@@ -60,7 +60,7 @@
    */
   setMode(newMode: DiffViewMode) {
     if (this.saveOnChange && this.mode && this.mode !== newMode) {
-      this.restApiService.savePreferences({diff_view: newMode});
+      this.userService.updatePreferences({diff_view: newMode});
     }
     this.mode = newMode;
     let announcement;
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts b/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts
index aa97394..8b06c75 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-mode-selector/gr-diff-mode-selector_test.ts
@@ -19,7 +19,7 @@
 import './gr-diff-mode-selector';
 import {GrDiffModeSelector} from './gr-diff-mode-selector';
 import {DiffViewMode} from '../../../constants/constants';
-import {stubRestApi} from '../../../test/test-utils';
+import {stubUsers} from '../../../test/test-utils';
 
 const basicFixture = fixtureFromElement('gr-diff-mode-selector');
 
@@ -47,7 +47,7 @@
   });
 
   test('setMode', () => {
-    const saveStub = stubRestApi('savePreferences');
+    const saveStub = stubUsers('updatePreferences');
 
     // Setting the mode initially does not save prefs.
     element.saveOnChange = true;
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.ts b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.ts
index 5b48345..c7a462e 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.ts
+++ b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.ts
@@ -113,6 +113,7 @@
 import {changeComments$} from '../../../services/comments/comments-model';
 import {takeUntil} from 'rxjs/operators';
 import {Subject} from 'rxjs';
+import {preferences$} from '../../../services/user/user-model';
 
 const ERR_REVIEW_STATUS = 'Couldn’t change file review status.';
 const LOADING_BLAME = 'Loading blame...';
@@ -361,11 +362,20 @@
     this._getLoggedIn().then(loggedIn => {
       this._loggedIn = loggedIn;
     });
+    // TODO(brohlfs): This just ensures that the userService is instantiated at
+    // all. We need the service to manage the model, but we are not making any
+    // direct calls. Will need to find a better solution to this problem ...
+    assertIsDefined(appContext.userService);
+
     changeComments$
       .pipe(takeUntil(this.disconnected$))
       .subscribe(changeComments => {
         this._changeComments = changeComments;
       });
+
+    preferences$.pipe(takeUntil(this.disconnected$)).subscribe(preferences => {
+      this._userPrefs = preferences;
+    });
     this.addEventListener('open-fix-preview', e => this._onOpenFixPreview(e));
     this.cursor.replaceDiffs([this.$.diffHost]);
     this._onRenderHandler = (_: Event) => {
@@ -1148,12 +1158,6 @@
 
     promises.push(this._getDiffPreferences());
 
-    promises.push(
-      this._getPreferences().then(prefs => {
-        this._userPrefs = prefs;
-      })
-    );
-
     if (!this._change) promises.push(this._getChangeDetail(this._changeNum));
 
     if (!this._changeComments) this._loadComments(value.patchNum);
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.js b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.js
index 2c4750a..0c7abc8 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view_test.js
@@ -1524,6 +1524,7 @@
       assert.equal(element._getDiffViewMode(), 'SIDE_BY_SIDE');
 
       // User prefs but no change view state set.
+      element.changeViewState.diffMode = undefined;
       element._userPrefs = {default_diff_view: 'UNIFIED_DIFF'};
       assert.equal(element._getDiffViewMode(), 'UNIFIED_DIFF');
 
diff --git a/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view.ts b/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view.ts
index 3533fd6..256e956 100644
--- a/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view.ts
+++ b/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view.ts
@@ -246,6 +246,7 @@
       this.$.diffPrefs.loadData(),
     ];
 
+    // TODO(dhruvsri): move this to the service
     promises.push(
       this.restApiService.getPreferences().then(prefs => {
         if (!prefs) {
diff --git a/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view_test.ts b/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view_test.ts
index 8194d5b..1165f1e 100644
--- a/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view_test.ts
+++ b/polygerrit-ui/app/elements/settings/gr-settings-view/gr-settings-view_test.ts
@@ -273,7 +273,7 @@
     stubRestApi('savePreferences').callsFake(prefs => {
       assertMenusEqual(prefs.my, preferences.my);
       assert.equal(prefs.publish_comments_on_push, true);
-      return Promise.resolve(new Response());
+      return Promise.resolve(createDefaultPreferences());
     });
 
     // Save the change.
@@ -294,7 +294,7 @@
 
     stubRestApi('savePreferences').callsFake(prefs => {
       assert.equal(prefs.publish_comments_on_push, true);
-      return Promise.resolve(new Response());
+      return Promise.resolve(createDefaultPreferences());
     });
 
     // Save the change.
@@ -315,7 +315,7 @@
 
     stubRestApi('savePreferences').callsFake(prefs => {
       assert.equal(prefs.work_in_progress_by_default, true);
-      return Promise.resolve(new Response());
+      return Promise.resolve(createDefaultPreferences());
     });
 
     // Save the change.
@@ -348,7 +348,7 @@
 
     stubRestApi('savePreferences').callsFake(prefs => {
       assertMenusEqual(prefs.my, element._localMenu);
-      return Promise.resolve(new Response());
+      return Promise.resolve(createDefaultPreferences());
     });
 
     await element._handleSaveMenu();
diff --git a/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands.ts b/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands.ts
index f808e38..8322682 100644
--- a/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands.ts
+++ b/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands.ts
@@ -73,6 +73,8 @@
 
   private readonly restApiService = appContext.restApiService;
 
+  private readonly userService = appContext.userService;
+
   disconnected$ = new Subject();
 
   override connectedCallback() {
@@ -106,7 +108,7 @@
     if (scheme && scheme !== this.selectedScheme) {
       this.set('selectedScheme', scheme);
       if (this._loggedIn) {
-        this.restApiService.savePreferences({
+        this.userService.updatePreferences({
           download_scheme: this.selectedScheme,
         });
       }
diff --git a/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands_test.ts b/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands_test.ts
index c932a2e..ef712ac 100644
--- a/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-download-commands/gr-download-commands_test.ts
@@ -23,6 +23,7 @@
 import {createPreferences} from '../../../test/test-data-generators';
 import * as MockInteractions from '@polymer/iron-test-helpers/mock-interactions';
 import {GrShellCommand} from '../gr-shell-command/gr-shell-command';
+import {createDefaultPreferences} from '../../../constants/constants';
 
 const basicFixture = fixtureFromElement('gr-download-commands');
 
@@ -95,7 +96,7 @@
     test('saves scheme to preferences', () => {
       element._loggedIn = true;
       const savePrefsStub = stubRestApi('savePreferences').returns(
-        Promise.resolve(new Response())
+        Promise.resolve(createDefaultPreferences())
       );
 
       flush();
diff --git a/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.ts b/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.ts
index f60b9b6..947ef3e 100644
--- a/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.ts
+++ b/polygerrit-ui/app/elements/shared/gr-label-info/gr-label-info.ts
@@ -43,6 +43,7 @@
   getApprovalInfo,
   getVotingRangeOrDefault,
   hasNeutralStatus,
+  hasVoted,
 } from '../../../utils/label-util';
 import {appContext} from '../../../services/app-context';
 import {ParsedChangeInfo} from '../../../types/types';
@@ -86,9 +87,21 @@
   @property({type: Object})
   account?: AccountInfo;
 
+  /**
+   * A user is able to delete a vote iff the mutable property is true and the
+   * reviewer that left the vote exists in the list of removable_reviewers
+   * received from the backend.
+   */
   @property({type: Boolean})
   mutable = false;
 
+  /**
+   * if true - show all reviewers that can vote on label
+   * if false - show only reviewers that voted on label
+   */
+  @property({type: Boolean})
+  showAllReviewers = true;
+
   private readonly restApiService = appContext.restApiService;
 
   private readonly reporting = appContext.reportingService;
@@ -201,7 +214,9 @@
     const labelInfo = this.labelInfo;
     if (!labelInfo) return;
     const reviewers = (this.change?.reviewers['REVIEWER'] ?? []).filter(
-      reviewer => canVote(labelInfo, reviewer)
+      reviewer =>
+        (this.showAllReviewers && canVote(labelInfo, reviewer)) ||
+        (!this.showAllReviewers && hasVoted(labelInfo, reviewer))
     );
     return html`<div>
       ${reviewers.map(reviewer => this.renderReviewerVote(reviewer))}
diff --git a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.ts b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.ts
index ae2bda0..63576c2 100644
--- a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.ts
+++ b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.ts
@@ -682,19 +682,27 @@
     });
   }
 
-  savePreferences(prefs: PreferencesInput): Promise<Response> {
+  savePreferences(
+    prefs: PreferencesInput
+  ): Promise<PreferencesInfo | undefined> {
     // Note (Issue 5142): normalize the download scheme with lower case before
     // saving.
     if (prefs.download_scheme) {
       prefs.download_scheme = prefs.download_scheme.toLowerCase();
     }
 
-    return this._restApiHelper.send({
-      method: HttpMethod.PUT,
-      url: '/accounts/self/preferences',
-      body: prefs,
-      reportUrlAsIs: true,
-    });
+    return this._restApiHelper
+      .send({
+        method: HttpMethod.PUT,
+        url: '/accounts/self/preferences',
+        body: prefs,
+        reportUrlAsIs: true,
+      })
+      .then((response: Response) =>
+        this.getResponseObject(response).then(
+          obj => obj as unknown as PreferencesInfo
+        )
+      );
   }
 
   saveDiffPreferences(prefs: DiffPreferenceInput): Promise<Response> {
diff --git a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.js b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.js
index 1aee75a..a60a1ef 100644
--- a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.js
+++ b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.js
@@ -386,7 +386,8 @@
       });
 
   test('savPreferences normalizes download scheme', () => {
-    const sendStub = sinon.stub(element._restApiHelper, 'send');
+    const sendStub = sinon.stub(element._restApiHelper, 'send').returns(
+        Promise.resolve(new Response()));
     element.savePreferences({download_scheme: 'HTTP'});
     assert.isTrue(sendStub.called);
     assert.equal(sendStub.lastCall.args[0].body.download_scheme, 'http');
diff --git a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api.ts b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api.ts
index cd3fab3..1378211 100644
--- a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api.ts
+++ b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api.ts
@@ -209,7 +209,9 @@
     errFn?: ErrorCallback
   ): Promise<ChangeInfo | null>;
 
-  savePreferences(prefs: PreferencesInput): Promise<Response>;
+  savePreferences(
+    prefs: PreferencesInput
+  ): Promise<PreferencesInfo | undefined>;
 
   getDiffPreferences(): Promise<DiffPreferencesInfo | undefined>;
 
diff --git a/polygerrit-ui/app/services/user/user-service.ts b/polygerrit-ui/app/services/user/user-service.ts
index 0612aca..125d20c 100644
--- a/polygerrit-ui/app/services/user/user-service.ts
+++ b/polygerrit-ui/app/services/user/user-service.ts
@@ -14,7 +14,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import {AccountDetailInfo, PreferencesInfo} from '../../types/common';
+import {
+  AccountDetailInfo,
+  PreferencesInfo,
+  PreferencesInput,
+} from '../../types/common';
 import {from, of} from 'rxjs';
 import {account$, updateAccount, updatePreferences} from './user-model';
 import {switchMap} from 'rxjs/operators';
@@ -39,4 +43,13 @@
         updatePreferences(preferences ?? createDefaultPreferences());
       });
   }
+
+  updatePreferences(prefs: PreferencesInput) {
+    this.restApiService
+      .savePreferences(prefs)
+      .then((newPrefs: PreferencesInfo | undefined) => {
+        if (!newPrefs) return;
+        updatePreferences(newPrefs);
+      });
+  }
 }
diff --git a/polygerrit-ui/app/test/mocks/gr-rest-api_mock.ts b/polygerrit-ui/app/test/mocks/gr-rest-api_mock.ts
index 4be19fd..3bb0c34 100644
--- a/polygerrit-ui/app/test/mocks/gr-rest-api_mock.ts
+++ b/polygerrit-ui/app/test/mocks/gr-rest-api_mock.ts
@@ -83,6 +83,7 @@
 import {
   createDefaultDiffPrefs,
   createDefaultEditPrefs,
+  createDefaultPreferences,
 } from '../../constants/constants';
 import {ParsedChangeInfo} from '../../types/types';
 
@@ -481,8 +482,8 @@
   saveIncludedGroup(): Promise<GroupInfo | undefined> {
     throw new Error('saveIncludedGroup() not implemented by RestApiMock.');
   },
-  savePreferences(): Promise<Response> {
-    return Promise.resolve(new Response());
+  savePreferences(): Promise<PreferencesInfo> {
+    return Promise.resolve(createDefaultPreferences());
   },
   saveRepoConfig(): Promise<Response> {
     return Promise.resolve(new Response());
diff --git a/polygerrit-ui/app/test/test-utils.ts b/polygerrit-ui/app/test/test-utils.ts
index 1cde372..39c30ad 100644
--- a/polygerrit-ui/app/test/test-utils.ts
+++ b/polygerrit-ui/app/test/test-utils.ts
@@ -24,6 +24,7 @@
 import {AuthService} from '../services/gr-auth/gr-auth';
 import {ReportingService} from '../services/gr-reporting/gr-reporting';
 import {CommentsService} from '../services/comments/comments-service';
+import {UserService} from '../services/user/user-service';
 export {query, queryAll, queryAndAssert} from '../utils/common-util';
 
 export interface MockPromise extends Promise<unknown> {
@@ -111,6 +112,10 @@
   return sinon.stub(appContext.commentsService, method);
 }
 
+export function stubUsers<K extends keyof UserService>(method: K) {
+  return sinon.stub(appContext.userService, method);
+}
+
 export function stubStorage<K extends keyof StorageService>(method: K) {
   return sinon.stub(appContext.storageService, method);
 }
diff --git a/polygerrit-ui/app/utils/label-util.ts b/polygerrit-ui/app/utils/label-util.ts
index 960b02f..a8a2719 100644
--- a/polygerrit-ui/app/utils/label-util.ts
+++ b/polygerrit-ui/app/utils/label-util.ts
@@ -92,8 +92,9 @@
 
 export function hasNeutralStatus(
   label: DetailedLabelInfo,
-  approvalInfo: ApprovalInfo
+  approvalInfo?: ApprovalInfo
 ) {
+  if (!approvalInfo) return true;
   return getLabelStatus(label, approvalInfo.value) === LabelStatus.NEUTRAL;
 }
 
@@ -134,6 +135,15 @@
   return label.all?.filter(x => x._account_id === account._account_id)[0];
 }
 
+export function hasVoted(label: LabelInfo, account: AccountInfo) {
+  if (isDetailedLabelInfo(label)) {
+    return !hasNeutralStatus(label, getApprovalInfo(label, account));
+  } else if (isQuickLabelInfo(label)) {
+    return label.approved === account || label.rejected === account;
+  }
+  return false;
+}
+
 export function canVote(label: DetailedLabelInfo, account: AccountInfo) {
   const approvalInfo = getApprovalInfo(label, account);
   if (!approvalInfo) return false;
diff --git a/tools/BUILD b/tools/BUILD
index 46671ac..e44ae78 100644
--- a/tools/BUILD
+++ b/tools/BUILD
@@ -241,7 +241,7 @@
         "-Xep:InstantTemporalUnit:ERROR",
         "-Xep:IntLongMath:ERROR",
         # "-Xep:InvalidBlockTag:WARN",
-        # "-Xep:InvalidInlineTag:WARN",
+        "-Xep:InvalidInlineTag:WARN",
         "-Xep:InvalidJavaTimeConstant:ERROR",
         "-Xep:InvalidLink:ERROR",
         # "-Xep:InvalidParam:WARN",
@@ -354,7 +354,7 @@
         "-Xep:OverridesGuiceInjectableMethod:ERROR",
         "-Xep:OverridesJavaxInjectableMethod:ERROR",
         "-Xep:PackageInfo:ERROR",
-        # "-Xep:ParameterName:WARN",
+        "-Xep:ParameterName:ERROR",
         "-Xep:ParametersButNotParameterized:ERROR",
         "-Xep:ParcelableCreator:ERROR",
         "-Xep:PeriodFrom:ERROR",