Sign inDemoInstall


Package Overview
File Explorer

Advanced tools

Install Socket

Protect your apps from supply chain attacks



Lightweight, robust, elegant syntax highlighting. A spin-off project from Dabblet.


Version published
Weekly downloads
increased by15.17%

Weekly downloads

Package description

What is prismjs?

PrismJS is a lightweight, extensible syntax highlighter, built with modern web standards in mind. It's used to make code snippets in web pages prettier and more readable. It supports a wide range of programming languages and comes with a variety of themes.

What are prismjs's main functionalities?

Syntax Highlighting

This feature allows you to highlight syntax of various programming languages. The code sample demonstrates how to highlight JavaScript code using PrismJS.

Prism.highlight(code, Prism.languages.javascript, 'javascript');

Extensible Language Definitions

PrismJS allows you to extend existing language definitions to add new patterns or modify existing ones. The code sample shows how to add a new pattern to the JavaScript language definition.

Prism.languages.insertBefore('javascript', 'function-variable', {
  'function-variable': {
    pattern: /\bvar\s+[a-z0-9_]+\s*=\s*function\b/,
    alias: 'function'

Custom Hooks

You can add custom hooks to modify code or the environment before or after the highlighting process. The code sample demonstrates a hook that replaces occurrences of 'foo' with 'bar' before highlighting.

Prism.hooks.add('before-highlight', function(env) {
  env.code = env.element.textContent.replace(/\bfoo\b/g, 'bar');


PrismJS comes with a variety of themes that can be easily included in your web page to change the appearance of highlighted code. The code sample shows how to include a PrismJS theme in an HTML document.

<link href="themes/prism.css" rel="stylesheet" />


PrismJS supports plugins that add additional functionality, such as displaying line numbers. The code sample demonstrates how to include the line numbers plugin.

<script src="plugins/line-numbers/prism-line-numbers.js"></script>

Other packages similar to prismjs



1.29.0 (2022-08-23)

New components

  • BBj (#3511) 1134bdfc
  • BQN (#3515) 859f99a0
  • Cilk/C & Cilk/C++ (#3522) c8462a29
  • Gradle (#3443) 32119823
  • METAFONT (#3465) 2815f699
  • WGSL (#3455) 4c87d418

Updated components

Updated plugins

  • Line Highlight
  • Normalize Whitespace





Build Status npm

Prism is a lightweight, robust, and elegant syntax highlighting library. It's a spin-off project from Dabblet.

You can learn more on

Why another syntax highlighter?

More themes for Prism!

Contribute to Prism!

Important Notice

We are currently working on Prism v2 and will only accept security-relevant PRs for the time being.

Once work on Prism v2 is sufficiently advanced, we will accept PRs again. This will be announced on our Discussion page and mentioned in the roadmap discussion.

Prism v1 contributing notes

Prism depends on community contributions to expand and cover a wider array of use cases. If you like it, consider giving back by sending a pull request. Here are a few tips:

  • Read the documentation. Prism was designed to be extensible.
  • Do not edit prism.js, it’s just the version of Prism used by the Prism website and is built automatically. Limit your changes to the unminified files in the components/ folder. prism.js and all minified files are generated by our build system (see below).
  • Use npm ci to install Prism's dependencies. Do not use npm install because it will cause non-deterministic builds.
  • The build system uses gulp to minify the files and build prism.js. With all of Prism's dependencies installed, you just need to run the command npm run build.
  • Please follow the code conventions used in the files already. For example, I use tabs for indentation and spaces for alignment. Opening braces are on the same line, closing braces on their own line regardless of construct. There is a space before the opening brace. etc etc.
  • Please try to err towards more smaller PRs rather than a few huge PRs. If a PR includes changes that I want to merge and also changes that I don't, handling it becomes difficult.
  • My time is very limited these days, so it might take a long time to review bigger PRs (small ones are usually merged very quickly), especially those modifying the Prism Core. This doesn't mean your PR is rejected.
  • If you contribute a new language definition, you will be responsible for handling bug reports about that language definition.
  • If you add a new language definition or plugin, you need to add it to components.json as well and rebuild Prism by running npm run build, so that it becomes available to the download build page. For new languages, please also add a few tests and an example in the examples/ folder.
  • Go to prism-themes if you want to add a new theme.

Thank you so much for contributing!!

Software requirements

Prism will run on almost any browser and Node.js version but you need the following software to contribute:

  • Node.js >= 10.x
  • npm >= 6.x




Last updated on 23 Aug 2022

Did you know?

Socket installs a GitHub app to automatically flag issues on every pull request and report the health of your dependencies. Find out what is inside your node modules and prevent malicious activity before you update the dependencies.


Related posts

SocketSocket SOC 2 Logo


  • Package Alerts
  • Integrations
  • Docs
  • Pricing
  • FAQ
  • Roadmap

Stay in touch

Get open source security insights delivered straight into your inbox.

  • Terms
  • Privacy
  • Security

Made with ⚡️ by Socket Inc