KaTeX

KaTeX
Name	KaTeX
Developer	Khan Academy and community
Released	13 December 2013
Latest release version	0.16.9
Latest release date	29 November 2023
Programming language	JavaScript
Genre	Typesetting, Mathematical notation
License	MIT License
Website	https://katex.org

KaTeX is a fast, easy-to-use JavaScript library for typesetting Mathematical notation on the web. Conceived and initially developed by engineers at Khan Academy, it was publicly released in late 2013 with the primary goal of rendering mathematical expressions significantly faster than existing solutions while maintaining high-quality output. Built with performance as a core design principle, it renders its markup directly to HTML and CSS, avoiding the use of PNG or SVG images, and supports a large subset of LaTeX syntax, making it a popular choice for developers, educators, and scientific communicators.

Overview

The project was initiated at Khan Academy to address performance bottlenecks encountered with other math rendering engines on their extensive educational platform, which features countless interactive exercises and articles. The lead developer, Emily Eisenberg, along with other contributors, focused on creating a library that could parse and render complex mathematical notation with minimal computational overhead, enabling seamless real-time updates in browser-based environments. Unlike systems that rely on generating rasterized images or complex Vector graphics, KaTeX compiles LaTeX expressions into static HTML elements styled with precise CSS, resulting in crisp rendering that scales perfectly with the surrounding text. This approach allows it to integrate effortlessly with modern web frameworks like React, Vue.js, and Angular, as well as static site generators such as Jekyll and Hugo.

Features

A key feature of KaTeX is its blistering rendering speed, often cited as being orders of magnitude faster than alternatives, which is critical for dynamic applications like the Khan Academy learning dashboard or interactive computational notebooks. It has no dependencies other than a web browser's native capabilities and supports a wide array of mathematical constructs including fractions, summations with Sigma notation, integrals, matrices, and multi-line equations through environments like `align`. The library provides server-side rendering support through Node.js, enabling pre-rendering of mathematical content for SEO purposes or for use in PDF generation pipelines. Furthermore, its output is designed to be accessible, with proper ARIA attributes and alternative text support to aid users of Screen reader software, aligning with modern Web Content Accessibility Guidelines.

Usage and syntax

Integrating KaTeX typically involves including its core JavaScript and CSS files in a webpage and then calling its rendering functions on DOM elements containing LaTeX expressions, which can be delimited by specific markers like `$$...$$` for display mathematics or `\(...\)` for inline mathematics. Many popular publishing platforms have built-in support or plugins for the library, including WordPress via the Jetpack plugin, GitHub's Markdown rendering, and documentation tools like Read the Docs and MkDocs. The syntax it accepts is deliberately a strict subset of standard LaTeX, omitting more complex and less frequently used TeX primitives to maintain its lightweight and predictable performance profile; for instance, it does not support the full `picture` environment but includes robust handling for `\newcommand` and `\def` for user-defined macros.

Comparison with other math rendering libraries

The most direct comparison is often made with MathJax, another venerable JavaScript library that aims for near-complete LaTeX and MathML compatibility, including the ability to re-render pages dynamically as a fallback for older browsers. While MathJax is exceptionally comprehensive, its larger codebase and different architectural approach can result in slower initial rendering, making KaTeX the preferred choice for performance-sensitive applications like the Khan Academy platform or real-time collaborative editors. Other alternatives include native browser support for MathML, which has seen renewed development interest from companies like Apple and Google but still suffers from inconsistent implementation across browsers like Firefox and Chrome, and older server-side image generation tools like mimeTeX.

Browser and platform support

KaTeX is designed to work across all modern web browsers, including Google Chrome, Mozilla Firefox, Safari, Microsoft Edge, and Opera, with consistent rendering from version 5.0 of Internet Explorer onwards. Its server-side rendering capability via Node.js ensures it can be used in diverse environments, from traditional web servers to Cloud computing platforms like AWS and Netlify. The library is also compatible with major Mobile browsers on iOS and Android, ensuring mathematical content is displayed correctly on the iPad and devices from manufacturers like Samsung. This broad compatibility, combined with its minimal footprint, makes it a versatile tool for the global educational and scientific community.

Development and community

Development is conducted openly on GitHub, where an active community of contributors from organizations like Khan Academy, Wikimedia Foundation, and Jupyter project collaborates on issues, feature requests, and Pull requests. The project is maintained under the permissive MIT License, encouraging adoption and integration into both open-source projects like Wikipedia and MediaWiki, and proprietary software from companies like Apple and Microsoft. Regular updates address bug fixes, expand LaTeX coverage, and improve performance, with the roadmap influenced by the needs of large-scale adopters and the evolving standards of the World Wide Web Consortium. Its success has cemented its role as a critical piece of infrastructure for the modern, mathematically-enabled web.

Category:JavaScript libraries Category:Mathematical software Category:Free software programmed in JavaScript