Java port of Google Prettify

Clone this repo:


  1. 32fa081 Fix BoxedPrimitiveEquality bug pattern flagged by error prone by David Ostrovsky · 10 months ago master
  2. 8af621b Add txt language by Fabien Sanglard · 1 year, 10 months ago
  3. 54d1c6c Fix visibility so it can be used by gitiles by Fabien Sanglard · 1 year, 10 months ago
  4. 1c676e8 Add BUILD and WORKSPACE to be usable by gitiles by Fabien Sanglard · 1 year, 11 months ago
  5. 2296a27 Use HTTPS links iso. HTTP by Han-Wen Nienhuys · 3 years, 3 months ago

Java Prettify

This library is a java port of Google Prettify, the current version ported is 4-Mar-2013. The copyright holder of the Google Prettify is Mike Samuel ( It is licensed under the Apache License Version 2. This port is distributed under Apache License Version 2.

If you need an editor more than a highlighter, please find jsyntaxpane.


Java SyntaxHighlighter


Java SE 6 or up

Language Supported

The comments in prettify.parser.Prettify are authoritative but the lexer should work on a number of languages including C and friends, Java, Python, Bash, SQL, HTML, XML, CSS, Javascript, Makefiles and Rust. It works passably on Ruby, PHP, VB, and Awk and a decent subset of Perl and Ruby, but, because of commenting conventions, doesn't work on Smalltalk, or CAML-like languages.

LISPy languages are supported via an extension: prettify.lang.LangLisp.

And similarly for Clojure, CSS, Go, Haskell, Lua, OCAML, SML, F#, Matlab, Nemerle, Protocol Buffers, Scala, SQL, TeX, LaTeX, VHDL, Visual Basic, WikiText, XQuery, and YAML.

If you'd like to add an extension for your favorite language, please look at prettify.lang.LangLisp.


Default, Desert, Sons of Obsidian, Sunburst


  • Allows you to change the first (starting) line number.
  • Allows you to turn gutter with line numbers on and off.
  • Allows you to highlight one or more lines to focus user's attention.


Note that this highlighter extends Swing component, so all operations are better be executed inside Swing dispatching thread.

import java.util.Arrays;
import java.util.logging.*;
import javax.swing.*;
import prettify.PrettifyParser;
import prettify.theme.ThemeDefault;
import syntaxhighlight.*;

public class Example {

  public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {

      public void run() {
        // the Prettify parser
        Parser parser = new PrettifyParser();

        // initialize the highlighter and use Default theme
        SyntaxHighlighter highlighter = new SyntaxHighlighter(parser, new ThemeDefault());
        // set the line number count from 10 instead of 1
        // set to highlight line 13, 27, 28, 38, 42, 43 and 53
        highlighter.setHighlightedLineList(Arrays.asList(13, 27, 28, 38, 42, 43, 53));
        try {
          highlighter.setContent(new File("test.html"));
        } catch (IOException ex) {
          Logger.getLogger(Example.class.getName()).log(Level.SEVERE, null, ex);

        JFrame frame = new JFrame();

Sample Screenshot

sample screenshot

Support & Discussion

Support & Discussion Group

Known Issues

  • Perl formatting is really crappy. Partly because Perl is hard to parse.