A free, private LaTeX equation editor that renders TeX math entirely in your browser. It is powered by KaTeX (KaTeX/KaTeX), in the projects own words "a fast, easy-to-use JavaScript library for TeX math rendering on the web" whose layout is "based on Donald Knuth's TeX, the gold standard for math typesetting." Type LaTeX into the source box and a debounced live preview renders the equation synchronously, the same approach KaTeX uses in production on Khan Academy, GitHub, Discord, and thousands of other sites. Toggle between display mode (a centered block equation) and inline mode (text-flow size) to match how the formula will appear in your document. A grouped symbol palette lets you insert common structures with one click: fractions \frac{a}{b}, square and nth roots, superscripts and subscripts, big operators like \sum, \prod, \int and \lim, the full Greek alphabet, relations and arrows, and ready-made matrix, cases, and aligned environments. Five sample equations (the quadratic formula, the Gaussian integral, Euler's identity, a matrix equation, and the Basel sum) load instantly so you can see real output and learn the syntax. KaTeX renders math synchronously without reflowing the page and produces the same output across Chrome, Safari, Firefox, Opera, and Edge, so the preview you see is the preview everyone sees. When a parse error occurs, throwOnError surfaces the exact KaTeX error message in red while a best-effort preview still shows the rest of the expression. Export your work three ways: copy the raw LaTeX source, copy the rendered HTML span markup that KaTeX produces, or copy clean MathML for accessible documents and tools that consume it. KaTeX has no dependencies and runs locally, so nothing you type is ever uploaded: there is no account, no API key, and no tracking.
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