Download websites that use KaTeX

About KaTeX

KaTeX exists because Khan Academy grew tired of watching equations shuffle into place after the rest of a lesson page had settled. The library it replaced laid out mathematics in stages, and the answer was to render in one synchronous pass with no reflow at all. Speed was the motive, but the side effect is what makes the detection interesting, because a library for typesetting mathematics is closer to a statement of subject matter than to infrastructure.

KaTeX is a JavaScript graphics from Khan Academy, first released in 2014, that renders TeX notation into HTML and CSS in the browser using JavaScript instead of leaving formulas to an image or a plugin. Nobody adds a math typesetter to a website by accident. The presence of KaTeX means somebody publishes equations often enough that formatting them by hand stopped being reasonable.

As of September 2026 we detect KaTeX on 30,302 sites. United States accounts for 19,024 of them, with .com as the common suffix. Concentration of that kind reflects where technical documentation and courseware get published in English more than it reflects where mathematics is taught, and the country column should be read in that spirit.

Who the population is matters more than how large it is. A domain that renders equations is a university department, a courseware or textbook publisher, a documentation site for a numerical library, a journal, a finance or engineering calculator, or a research blog kept by one person. Anyone selling into education technology, academic publishing, or research software is looking for precisely that set of domains, and a keyword crawl does not find it cleanly, because the mathematics on those pages exists as markup rather than as text a crawler can read.

The limits are worth stating. Detection depends on the script or the stylesheet being loaded from a path we can recognise, so a copy renamed and self hosted inside a theme drops out. Version information is thin for this library, because the files are commonly served without a version anywhere in the path, which means the export cannot be filtered by release the way a dependency audit would want. A template that loads the renderer sitewide also registers on the whole domain even when a handful of pages carry an equation, so a row means a publisher who works with mathematical content rather than a page full of it.

Used with that in mind, the download answers a question no per domain lookup reaches. Checking one address tells you a single institution renders formulas client side. The list tells you how many such publishers exist, which markets they sit in, and which suffixes they register under, which is the difference between a curiosity and an addressable population.