highlight.js

What is highlight.js?

The highlight.js npm package is a syntax highlighter written in JavaScript. It's used to add syntax highlighting to code blocks on web pages, making them more readable and aesthetically pleasing. It supports a wide range of programming languages and is commonly used in blogs, forums, and other platforms where code is shared.

What are highlight.js's main functionalities?

Syntax Highlighting

Automatically detects and highlights syntax in code blocks on a webpage. This is the most basic usage where it applies highlighting to all code blocks.

hljs.highlightAll();

Custom Language Selection

Highlights a specific code element with a specified language. This allows for more control over which elements are highlighted and in what language.

hljs.highlightElement(document.getElementById('my-code'), {language: 'javascript', ignoreIllegals: true});

Custom Themes

Allows the use of custom themes for syntax highlighting. Themes are available as separate CSS files that can be imported to change the appearance of highlighted code.

import 'highlight.js/styles/atom-one-dark.css';

Line Numbers

Adds line numbers to code blocks. This feature is often used in conjunction with syntax highlighting to improve readability and reference specific lines of code.

document.addEventListener('DOMContentLoaded', (event) => { document.querySelectorAll('pre code').forEach((block) => { hljs.lineNumbersBlock(block); }); });

Other packages similar to highlight.js

PrismJS

PrismJS is another syntax highlighter that is similar to highlight.js. It is known for its lightweight core and extensible plugin system. Unlike highlight.js, PrismJS allows users to extend its functionality with plugins for features like line numbers, show language, and copy to clipboard.

CodeMirror

CodeMirror is not just a syntax highlighter but a versatile text editor implemented in JavaScript for the browser. It provides more features than highlight.js, including code editing, real-time collaboration, and linting. However, it is heavier and more complex to integrate.

Ace

Ace is an embeddable code editor written in JavaScript, similar to CodeMirror. It offers syntax highlighting as one of its features, along with a range of other editing features. It is more suitable for applications that require a full-fledged editor rather than just syntax highlighting.