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KaTeX

A fast JavaScript library that renders LaTeX-style math in web pages.

Stars
20.5k
Forks
1.3k
Licence
MIT
Language
TypeScript
Last update
7 days ago
Type
Library

What it is

KaTeX is a JavaScript library that takes math written in TeX/LaTeX notation and draws it on a web page as formatted equations. It runs in the browser or on a server, and the README says it renders synchronously without reflowing the page. It supports much, but not all, of LaTeX.

  • Render inline or display formulas in a blog or documentation site
  • Pre-render equations on a Node.js server with renderToString and send static HTML
  • Show formulas in a web app with katex.render into a DOM element
  • Automatically find and render math in a page using the auto-render extension

Great for

  • Website builders who want readable equations in articles, docs or course pages
  • Developers adding math to a web app who want a lightweight renderer
  • Teams that pre-render math on a server and send plain HTML to visitors
  • Anyone who already writes formulas in LaTeX syntax

Not ideal for

  • People who need full LaTeX support, since the README says KaTeX supports only much but not all of LaTeX and many packages
  • Projects that need a renderer for non-math documents or full typesetting of whole pages
  • Users who cannot load its CSS and font files, since the README says they must be included for rendering to work
Step-by-step guide: how to use KaTeXInstall, first run, examples, tips and FAQs

How to get it

  1. 1

    Install with a package manager

    Load KaTeX from the jsDelivr CDN (copy the link tags from the starter template)

    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.19.1/dist/katex.min.css">

    Clone the repository

    git clone https://github.com/KaTeX/KaTeX
  2. 2

    Run it

    • Add the KaTeX stylesheet and script tags to your HTML page, using an HTML5 doctype
    • Create an empty element on the page where the formula should appear
    • Call katex.render with your TeX string and the element, using throwOnError: false
    • Open the page in a browser to check that the formula displays
  3. 3

    Get the most out of it

    • Use the auto-render extension to render all math in a page without calling render by hand (see the autorender docs linked in the README)
    • Use renderToString for server-side rendering so visitors receive plain HTML and need no client-side JavaScript
    • Set throwOnError: false so invalid input shows as red source text with an error hover instead of breaking the page
    • Check the supported functions list at katex.org/docs/supported.html before relying on a specific command

Downloads

Strengths

  • Fast, synchronous rendering that does not need to reflow the page, per the README
  • No dependencies and easy to bundle with your site's resources
  • Produces the same output regardless of browser or environment, which suits server-side rendering

Trade-offs

  • Supports only a subset of LaTeX and many LaTeX packages, so some formulas may not work
  • Requires the HTML5 doctype and the included CSS and font files, or rendering may fail
  • Using the CDN links depends on an outside host unless you download and host the files yourself

How it compares

ProjectStarsTypeLevelUpdatedBest for
KaTeX (this)20.5kLibrarybeginner7 days agoWebsite builders who want readable equations in articles, docs or course pages
editor.md14.3kLibrarybeginner2.5 years agoWeb developers who want a Markdown input box inside their own site or admin panel
manim42.1kLibraryintermediate4 days agoProgrammers who want to make math or science explainer videos
PlotNeuralNet25.1kLibraryintermediate3.2 years agoResearchers who want clean architecture figures for papers
gpu.js15.5kLibraryintermediate6 days agoDevelopers who need to speed up large numeric computations in the browser

Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.