An embeddable script that makes source-code snippets in HTML prettier.

• Works on HTML pages.
• Works even if code contains embedded links, line numbers, etc.
• Simple API: include some JS & CSS and add an onload handler.
• Lightweights: small download and does not block page from loading while running.
• Customizable styles via CSS. See the themes gallery.
• Supports all C-like, Bash-like, and XML-like languages. No need to specify the language.
• Extensible language handlers for other languages. You can specify the language.
• Widely used with good cross-browser support. Powers https://code.google.com/ and http://stackoverflow.com/

See an example.

• Include the script tag below in your document:

<script src="https://cdn.rawgit.com/google/code-prettify/master/loader/run_prettify.js"></script>

• See Getting Started to configure that URL with options you need.
• Look at the skin gallery and pick styles that suit you.

Put code snippets in <pre class="prettyprint">...</pre> or <code class="prettyprint">...</code> and it will automatically be pretty-printed.

<pre class="prettyprint">class Voila {
public:
  // Voila
  static const string VOILA = "Voila";

  // will not interfere with embedded <a href="#voila2">tags</a>.
}</pre>

The comments in prettify.js are authoritative but the lexer should work on a number of languages including C and friends, Java, Python, Bash, SQL, HTML, XML, CSS, JavaScript, Makefile, 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, OCaml, etc. without a language extension.

Other languages are supported via extensions:

Apollo; Basic; Clojure; CSS; Dart; Erlang; Go; Haskell; Lasso; Lisp, Scheme; LLVM; Logtalk; Lua; MATLAB; MLs: F#, Ocaml,SML; Mumps; Nemerle; Pascal; Protocol buffers; R, S; RD; Rust; Scala; SQL; Swift; TCL; LaTeX; Visual Basic; VHDL; Wiki; XQ; YAML

If you'd like to add an extension for your favorite language, please look at src/lang-lisp.js and submit a pull request.

You don't need to specify the language since PR.prettyPrint() will guess. You can specify a language by specifying the language extension along with the prettyprint class:

<pre class="prettyprint lang-html">
  The lang-* class specifies the language file extensions.
  File extensions supported by default include:
    "bsh", "c", "cc", "cpp", "cs", "csh", "cyc", "cv", "htm", "html", "java",
    "js", "m", "mxml", "perl", "pl", "pm", "py", "rb", "sh", "xhtml", "xml",
    "xsl".
</pre>

You may also use the HTML 5 convention of embedding a <code> element inside the <pre> and using language-java style classes:

<pre class="prettyprint"><code class="language-java">...</code></pre>

Yes. Prettifying obfuscated code is like putting lipstick on a pig — i.e. outside the scope of this tool.

It's been tested with IE 6, Firefox 1.5 & 2, and Safari 2.0.4. Look at the tests to see if it works in your browser.

See the changelog.

Apparently wordpress does "smart quoting" which changes close quotes. This causes end quotes to not match up with open quotes.

This breaks prettifying as well as copying and pasting of code samples. See WordPress's help center for info on how to stop smart quoting of code snippets.

You can use the linenums class to turn on line numbering. If your code doesn't start at line number 1, you can add a colon and a line number to the end of that class as in linenums:52. For example:

<pre class="prettyprint linenums:4"
>// This is line 4.
foo();
bar();
baz();
boo();
far();
faz();
</pre>

You can use the nocode class to identify a span of markup that is not code:

<pre class="prettyprint">
int x = foo();  /* This is a comment  <span class="nocode">This is not code</span>
  Continuation of comment */
int y = bar();
</pre>

For a more complete example see the issue #22 testcase.

If you are calling prettyPrint via an event handler, wrap it in a function. Instead of doing:

addEventListener('load', PR.prettyPrint, false);

wrap it in a closure like:

addEventListener('load', function(event) { PR.prettyPrint(); }, false);

so that the browser does not pass an event object to PR.prettyPrint which will confuse it.

Prettify adds <span> with classes describing the kind of code. You can create CSS styles to matches these classes.

See the theme gallery for examples.

Instead of <pre class="prettyprint ..."> you can use a comment or processing instructions that survives processing instructions: <?prettify ...?> works as explained in Getting Started.

Prettify puts lines into an HTML list element so that line numbers aren't caught by copy/paste, and the line numbering is controlled by CSS in the default stylesheet, prettify.css.

The following should turn line numbering back on for the other lines:

<style>
li.L0, li.L1, li.L2, li.L3,
li.L5, li.L6, li.L7, li.L8 {
  list-style-type: decimal !important;
}
</style>

Please use the official support group for discussions, suggestions, and general feedback.

Apache License 2.0