MetaPost and TikZ,
with real LaTeX

What it does

Not a reimplementation of either language, but the real programs.

The engines are the programs from TeX Live 2025, compiled to WebAssembly, so anything that typesets on a TeX installation typesets here, and the output is the same to the byte.

Using it

On a web page, a single script tag is enough. Diagrams are written straight into the HTML, and each is replaced by its SVG:

<script type="module" src="/path/to/dist/auto.js"></script>

<script type="text/tikz" data-libraries="arrows.meta">
  \begin{tikzpicture} \draw[->,thick] (0,0) -- (2,1) node[right] {$x^2$}; \end{tikzpicture}
</script>
<script type="text/metapost">draw fullcircle scaled 50; label.top(btex $\int_0^1 x\,dx$ etex, (0,25));</script>

From JavaScript, the API returns the figures and pages directly:

import { MetaPost } from './dist/index.js';
const mp  = await MetaPost.create();
const fig = await mp.run('beginfig(1); draw fullcircle scaled 100; endfig; end.');
const doc = await mp.latex(String.raw`\documentclass[tikz]{standalone}
  \begin{document}\tikz\shade[ball color=blue!60] (0,0) circle (1);\end{document}`);
document.body.innerHTML = fig.figures[0].svg + doc.pages[0];

The feature guide covers every option, rendered by the engines themselves — among its examples a paragraph set inside a circle by TeX's \parshape, with inline TikZ pictures and displayed mathematics, which is the kind of thing a real TeX can do and a picture-only engine cannot.

Demos

Everything on these pages is rendered in your browser by the WebAssembly engines.

Get it

The prebuilt release is what most people want. Download mp-tikz-wasm-0.5.0.tar.gz or .zip from the releases page and unpack it: it holds the compiled engines, the JavaScript, the bundles and these demo pages, and needs neither TeX Live nor Emscripten.

tar xzf mp-tikz-wasm-0.5.0.tar.gz && cd mp-tikz-wasm-0.5.0
node serve.mjs 8080        # then open http://localhost:8080/site/

Host the dist/ folder on any static server — plain files, no special headers — and add the one script line to your page, or import dist/index.js. Building from source, with the twelve upstream patches each explained, is described in the repository.

Licences

mp-tikz-wasm's own code is under the LGPL-3.0. Each upstream program it builds keeps its own licence — the TeX engines and dvisvgm are distributed under the GPL — and NOTICE.md sets out what applies to what.