Highlight.js is a syntax highlighter written in JavaScript. It works in
the browser as well as on the server. It can work with pretty much any
markup, doesn’t depend on any other frameworks, and has automatic language
detection.
As always, major releases do contain breaking changes which may require action from users. Please read VERSION_11_UPGRADE.md for a detailed summary of breaking changes and any actions you may need to take.
Support for older versions
Please see SECURITY.md for long-term support information.
Basic Usage
In the Browser
The bare minimum for using highlight.js on a web page is linking to the
library along with one of the themes and calling highlightAll:
This will find and highlight code inside of <pre><code> tags; it tries
to detect the language automatically. If automatic detection doesn’t
work for you, or you simply prefer to be explicit, you can specify the language manually in the using the class attribute:
<pre><codeclass="language-html">...</code></pre>
Plaintext Code Blocks
To apply the Highlight.js styling to plaintext without actually highlighting it, use the plaintext language:
See Importing the Library for more examples of require vs import usage, etc. For more information about the result object returned by highlight or highlightAuto refer to the api docs.
Supported Languages
Highlight.js supports over 180 languages in the core library. There are also 3rd party
language definitions available to support even more languages. You can find the full list of supported languages in SUPPORTED_LANGUAGES.md.
Custom Usage
If you need a bit more control over the initialization of
Highlight.js, you can use the highlightElement and configure
functions. This allows you to better control what to highlight and when.
For example, here’s the rough equivalent of calling highlightAll but doing the work manually instead:
Please refer to the documentation for configure options.
Using custom HTML
We strongly recommend <pre><code> wrapping for code blocks. It's quite
semantic and "just works" out of the box with zero fiddling. It is possible to
use other HTML elements (or combos), but you may need to pay special attention to
preserving linebreaks.
Let's say your markup for code blocks uses divs:
<divclass='code'>...</div>
To highlight such blocks manually:
// first, find all the div.code blocksdocument.querySelectorAll('div.code').forEach(el=>{// then highlight eachhljs.highlightElement(el);});
Without using a tag that preserves linebreaks (like pre) you'll need some
additional CSS to help preserve them. You could also pre and post-process line
breaks with a plug-in, but we recommend using CSS.
<divid="app"><!-- bind to a data property named `code` --><highlightjsautodetect:code="code" />
<!-- or literal code works as well --><highlightjslanguage='javascript' code="var x = 5;" />
</div>
Using Web Workers
You can run highlighting inside a web worker to avoid freezing the browser
window while dealing with very big chunks of code.
First, you'll likely be installing the library via npm or yarn -- see Getting the Library.
Node.js / require
Requiring the top-level library will load all languages:
// require the highlight.js library, including all languagesconsthljs=require('./highlight.js');consthighlightedCode=hljs.highlightAuto('<span>Hello World!</span>').value
For a smaller footprint, load our common subset of languages (the same set used for our default web build).
consthljs=require('highlight.js/lib/common');
For the smallest footprint, load only the languages you need:
Note: You can also import directly from fully static URLs, such as our very own pre-built
ES6 Module CDN resources. See Fetch via CDN for specific examples.
The default import will register all languages:
importhljsfrom'highlight.js';
It is more efficient to import only the library and register the languages you need:
You can get highlight.js as a hosted, or custom-build, browser script or
as a server module. Right out of the box the browser script supports
both AMD and CommonJS, so if you wish you can use RequireJS or
Browserify without having to build from source. The server module also
works perfectly fine with Browserify, but there is the option to use a
build specific to browsers rather than something meant for a server.
Do not link to GitHub directly. The library is not supposed to work straight
from the source, it requires building. If none of the pre-packaged options
work for you refer to the building documentation.
On Almond. You need to use the optimizer to give the module a name. For
example:
A prebuilt version of Highlight.js bundled with many common languages is hosted by several popular CDNs.
When using Highlight.js via CDN you can use Subresource Integrity for additional security. For details
see DIGESTS.md.
<linkrel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.5.0/styles/default.min.css"><scriptsrc="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.5.0/highlight.min.js"></script><!-- and it's easy to individually load additional languages --><scriptsrc="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.5.0/languages/go.min.js"></script>
ES6 Modules
<linkrel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.5.0/styles/dark.min.css"><scripttype="module">importhljsfrom'https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.5.0/es/highlight.min.js';// and it's easy to individually load additional languagesimportgofrom'https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.5.0/es/languages/go.min.js';hljs.registerLanguage('go',go);</script>
<linkrel="stylesheet" href="https://cdn.jsdelivr.net/gh/highlightjs/[email protected]/build/styles/default.min.css"><scriptsrc="https://cdn.jsdelivr.net/gh/highlightjs/[email protected]/build/highlight.min.js"></script><!-- and it's easy to individually load additional languages --><scriptsrc="https://cdn.jsdelivr.net/gh/highlightjs/[email protected]/build/languages/go.min.js"></script>
ES6 Modules
<linkrel="stylesheet" href="https://cdn.jsdelivr.net/gh/highlightjs/[email protected]/build/styles/default.min.css"><scripttype="module">importhljsfrom'https://cdn.jsdelivr.net/gh/highlightjs/[email protected]/build/es/highlight.min.js';// and it's easy to individually load additional languagesimportgofrom'https://cdn.jsdelivr.net/gh/highlightjs/[email protected]/build/es/languages/go.min.js';hljs.registerLanguage('go',go);</script>
<linkrel="stylesheet" href="https://unpkg.com/@highlightjs/[email protected]/styles/default.min.css"><scriptsrc="https://unpkg.com/@highlightjs/[email protected]/highlight.min.js"></script><!-- and it's easy to individually load additional languages --><scriptsrc="https://unpkg.com/@highlightjs/[email protected]/languages/go.min.js"></script>
ES6 Modules
<linkrel="stylesheet" href="https://unpkg.com/@highlightjs/[email protected]/styles/default.min.css"><scripttype="module">importhljsfrom'https://unpkg.com/@highlightjs/[email protected]/es/highlight.min.js';// and it's easy to individually load & register additional languagesimportgofrom'https://unpkg.com/@highlightjs/[email protected]/es/languages/go.min.js';hljs.registerLanguage('go',go);</script>
Note:The CDN-hosted highlight.min.js package doesn't bundle every language. It would be
very large. You can find our list of "common" languages that we bundle by default on our download page.