diff --git a/java/com/google/gerrit/server/project/RefUtil.java b/java/com/google/gerrit/server/project/RefUtil.java
index 1dac751..5d6379a 100644
--- a/java/com/google/gerrit/server/project/RefUtil.java
+++ b/java/com/google/gerrit/server/project/RefUtil.java
@@ -19,6 +19,7 @@
 
 import com.google.common.collect.Iterables;
 import com.google.common.flogger.FluentLogger;
+import com.google.gerrit.common.Nullable;
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.entities.RefNames;
 import com.google.gerrit.extensions.restapi.BadRequestException;
@@ -46,16 +47,15 @@
     try {
       ObjectId revid = repo.resolve(baseRevision);
       if (revid == null) {
-        throw new InvalidRevisionException();
+        throw new InvalidRevisionException(baseRevision);
       }
       return revid;
     } catch (IOException err) {
       logger.atSevere().withCause(err).log(
           "Cannot resolve \"%s\" in project \"%s\"", baseRevision, projectName.get());
-      throw new InvalidRevisionException();
+      throw new InvalidRevisionException(baseRevision);
     } catch (RevisionSyntaxException err) {
-      logger.atSevere().withCause(err).log("Invalid revision syntax \"%s\"", baseRevision);
-      throw new InvalidRevisionException();
+      throw new InvalidRevisionException(baseRevision);
     }
   }
 
@@ -66,7 +66,7 @@
       try {
         rw.markStart(rw.parseCommit(revid));
       } catch (IncorrectObjectTypeException err) {
-        throw new InvalidRevisionException();
+        throw new InvalidRevisionException(revid.name());
       }
       RefDatabase refDb = repo.getRefDatabase();
       Iterable<Ref> refs =
@@ -86,11 +86,11 @@
       rw.checkConnectivity();
       return rw;
     } catch (IncorrectObjectTypeException | MissingObjectException err) {
-      throw new InvalidRevisionException();
+      throw new InvalidRevisionException(revid.name());
     } catch (IOException err) {
       logger.atSevere().withCause(err).log(
           "Repository \"%s\" may be corrupt; suggest running git fsck", repo.getDirectory());
-      throw new InvalidRevisionException();
+      throw new InvalidRevisionException(revid.name());
     }
   }
 
@@ -125,8 +125,8 @@
 
     public static final String MESSAGE = "Invalid Revision";
 
-    InvalidRevisionException() {
-      super(MESSAGE);
+    InvalidRevisionException(@Nullable String invalidRevision) {
+      super(MESSAGE + ": " + invalidRevision);
     }
   }
 }
diff --git a/java/com/google/gerrit/server/restapi/project/CreateBranch.java b/java/com/google/gerrit/server/restapi/project/CreateBranch.java
index 56948c1..67213c5 100644
--- a/java/com/google/gerrit/server/restapi/project/CreateBranch.java
+++ b/java/com/google/gerrit/server/restapi/project/CreateBranch.java
@@ -16,6 +16,7 @@
 
 import static com.google.gerrit.entities.RefNames.isConfigRef;
 
+import com.google.common.base.Strings;
 import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.entities.BranchNameKey;
 import com.google.gerrit.entities.RefNames;
@@ -93,7 +94,10 @@
     if (input.ref != null && !ref.equals(input.ref)) {
       throw new BadRequestException("ref must match URL");
     }
-    if (input.revision == null) {
+    if (input.revision != null) {
+      input.revision = input.revision.trim();
+    }
+    if (Strings.isNullOrEmpty(input.revision)) {
       input.revision = Constants.HEAD;
     }
     while (ref.startsWith("/")) {
diff --git a/java/com/google/gerrit/server/restapi/project/CreateTag.java b/java/com/google/gerrit/server/restapi/project/CreateTag.java
index dca6e9a..8fdf5e4 100644
--- a/java/com/google/gerrit/server/restapi/project/CreateTag.java
+++ b/java/com/google/gerrit/server/restapi/project/CreateTag.java
@@ -88,7 +88,10 @@
     if (input.ref != null && !ref.equals(input.ref)) {
       throw new BadRequestException("ref must match URL");
     }
-    if (input.revision == null) {
+    if (input.revision != null) {
+      input.revision = input.revision.trim();
+    }
+    if (Strings.isNullOrEmpty(input.revision)) {
       input.revision = Constants.HEAD;
     }
 
diff --git a/javatests/com/google/gerrit/acceptance/rest/project/CreateBranchIT.java b/javatests/com/google/gerrit/acceptance/rest/project/CreateBranchIT.java
index e5ef5ba..85d383e 100644
--- a/javatests/com/google/gerrit/acceptance/rest/project/CreateBranchIT.java
+++ b/javatests/com/google/gerrit/acceptance/rest/project/CreateBranchIT.java
@@ -36,9 +36,11 @@
 import com.google.gerrit.extensions.api.projects.BranchInfo;
 import com.google.gerrit.extensions.api.projects.BranchInput;
 import com.google.gerrit.extensions.restapi.AuthException;
+import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.inject.Inject;
+import org.eclipse.jgit.revwalk.RevCommit;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -146,6 +148,116 @@
         "Not allowed to create group branch.");
   }
 
+  @Test
+  public void createWithRevision() throws Exception {
+    RevCommit revision = projectOperations.project(project).getHead("master");
+
+    // update master so that points to a different revision than the revision on which we create the
+    // new branch
+    pushTo("refs/heads/master");
+    assertThat(projectOperations.project(project).getHead("master")).isNotEqualTo(revision);
+
+    BranchInput input = new BranchInput();
+    input.revision = revision.name();
+    BranchInfo created = branch(testBranch).create(input).get();
+    assertThat(created.ref).isEqualTo(testBranch.branch());
+    assertThat(created.revision).isEqualTo(revision.name());
+    assertThat(projectOperations.project(project).getHead(testBranch.branch())).isEqualTo(revision);
+  }
+
+  @Test
+  public void createWithoutSpecifyingRevision() throws Exception {
+    // If revision is not specified, the branch is created based on HEAD, which points to master.
+    RevCommit expectedRevision = projectOperations.project(project).getHead("master");
+
+    BranchInput input = new BranchInput();
+    input.revision = null;
+    BranchInfo created = branch(testBranch).create(input).get();
+    assertThat(created.ref).isEqualTo(testBranch.branch());
+    assertThat(created.revision).isEqualTo(expectedRevision.name());
+    assertThat(projectOperations.project(project).getHead(testBranch.branch()))
+        .isEqualTo(expectedRevision);
+  }
+
+  @Test
+  public void createWithEmptyRevision() throws Exception {
+    // If revision is not specified, the branch is created based on HEAD, which points to master.
+    RevCommit expectedRevision = projectOperations.project(project).getHead("master");
+
+    BranchInput input = new BranchInput();
+    input.revision = "";
+    BranchInfo created = branch(testBranch).create(input).get();
+    assertThat(created.ref).isEqualTo(testBranch.branch());
+    assertThat(created.revision).isEqualTo(expectedRevision.name());
+    assertThat(projectOperations.project(project).getHead(testBranch.branch()))
+        .isEqualTo(expectedRevision);
+  }
+
+  @Test
+  public void createRevisionIsTrimmed() throws Exception {
+    RevCommit revision = projectOperations.project(project).getHead("master");
+
+    BranchInput input = new BranchInput();
+    input.revision = "\t" + revision.name();
+    BranchInfo created = branch(testBranch).create(input).get();
+    assertThat(created.ref).isEqualTo(testBranch.branch());
+    assertThat(created.revision).isEqualTo(revision.name());
+    assertThat(projectOperations.project(project).getHead(testBranch.branch())).isEqualTo(revision);
+  }
+
+  @Test
+  public void createWithBranchNameAsRevision() throws Exception {
+    RevCommit expectedRevision = projectOperations.project(project).getHead("master");
+
+    BranchInput input = new BranchInput();
+    input.revision = "master";
+    BranchInfo created = branch(testBranch).create(input).get();
+    assertThat(created.ref).isEqualTo(testBranch.branch());
+    assertThat(created.revision).isEqualTo(expectedRevision.name());
+    assertThat(projectOperations.project(project).getHead(testBranch.branch()))
+        .isEqualTo(expectedRevision);
+  }
+
+  @Test
+  public void createWithFullBranchNameAsRevision() throws Exception {
+    RevCommit expectedRevision = projectOperations.project(project).getHead("master");
+
+    BranchInput input = new BranchInput();
+    input.revision = "refs/heads/master";
+    BranchInfo created = branch(testBranch).create(input).get();
+    assertThat(created.ref).isEqualTo(testBranch.branch());
+    assertThat(created.revision).isEqualTo(expectedRevision.name());
+    assertThat(projectOperations.project(project).getHead(testBranch.branch()))
+        .isEqualTo(expectedRevision);
+  }
+
+  @Test
+  public void cannotCreateWithNonExistingBranchNameAsRevision() throws Exception {
+    assertCreateFails(
+        testBranch,
+        "refs/heads/non-existing",
+        BadRequestException.class,
+        "invalid revision \"refs/heads/non-existing\"");
+  }
+
+  @Test
+  public void cannotCreateWithNonExistingRevision() throws Exception {
+    assertCreateFails(
+        testBranch,
+        "deadbeefdeadbeefdeadbeefdeadbeefdeadbeef",
+        BadRequestException.class,
+        "invalid revision \"deadbeefdeadbeefdeadbeefdeadbeefdeadbeef\"");
+  }
+
+  @Test
+  public void cannotCreateWithInvalidRevision() throws Exception {
+    assertCreateFails(
+        testBranch,
+        "invalid\trevision",
+        BadRequestException.class,
+        "invalid revision \"invalid\trevision\"");
+  }
+
   private void blockCreateReference() throws Exception {
     projectOperations
         .project(project)
diff --git a/javatests/com/google/gerrit/acceptance/rest/project/TagsIT.java b/javatests/com/google/gerrit/acceptance/rest/project/TagsIT.java
index 3d1a148..3becb81 100644
--- a/javatests/com/google/gerrit/acceptance/rest/project/TagsIT.java
+++ b/javatests/com/google/gerrit/acceptance/rest/project/TagsIT.java
@@ -41,6 +41,7 @@
 import com.google.inject.Inject;
 import java.sql.Timestamp;
 import java.util.List;
+import org.eclipse.jgit.revwalk.RevCommit;
 import org.junit.Test;
 
 @NoHttpd
@@ -357,6 +358,53 @@
     assertThat(thrown).hasMessageThat().contains("Invalid base revision");
   }
 
+  @Test
+  public void noBaseRevision() throws Exception {
+    grantTagPermissions();
+
+    // If revision is not specified, the tag is created based on HEAD, which points to master.
+    RevCommit expectedRevision = projectOperations.project(project).getHead("master");
+
+    TagInput input = new TagInput();
+    input.ref = "test";
+    input.revision = null;
+
+    TagInfo result = tag(input.ref).create(input).get();
+    assertThat(result.ref).isEqualTo(R_TAGS + input.ref);
+    assertThat(result.revision).isEqualTo(expectedRevision.name());
+  }
+
+  @Test
+  public void emptyBaseRevision() throws Exception {
+    grantTagPermissions();
+
+    // If revision is not specified, the tag is created based on HEAD, which points to master.
+    RevCommit expectedRevision = projectOperations.project(project).getHead("master");
+
+    TagInput input = new TagInput();
+    input.ref = "test";
+    input.revision = "";
+
+    TagInfo result = tag(input.ref).create(input).get();
+    assertThat(result.ref).isEqualTo(R_TAGS + input.ref);
+    assertThat(result.revision).isEqualTo(expectedRevision.name());
+  }
+
+  @Test
+  public void baseRevisionIsTrimmed() throws Exception {
+    grantTagPermissions();
+
+    RevCommit revision = projectOperations.project(project).getHead("master");
+
+    TagInput input = new TagInput();
+    input.ref = "test";
+    input.revision = "\t" + revision.name();
+
+    TagInfo result = tag(input.ref).create(input).get();
+    assertThat(result.ref).isEqualTo(R_TAGS + input.ref);
+    assertThat(result.revision).isEqualTo(revision.name());
+  }
+
   private void assertTagList(FluentIterable<String> expected, List<TagInfo> actual)
       throws Exception {
     assertThat(actual).hasSize(expected.size());