Paste your LaTeX source into the editor and see it rendered beside it, instantly. Math is typeset with KaTeX, so equations, fractions, matrices, aligned blocks, Greek letters, and the common AMS-math commands update in real time as you type. Document structure is rendered too: numbered chapters and sections, itemize and enumerate lists (including enumitem labels), booktabs tables, figures with captions, and the theorem environments you declare with \newtheorem, numbered as LaTeX would number them. Equations in equation, align, gather and multline share one counter, each align row gets its own number, and \eqref and \cref point to the right row. Everything runs locally in your browser: your .tex is never uploaded to a server unless you choose PDF export.
This preview is built for quick checks while you write: does that equation compile, is the table shaped right, did the section numbering come out as expected. KaTeX covers the large majority of everyday math, and the macros and operators you define in the preamble are expanded. It is not a full TeX engine, though: page layout, package-specific styling, custom document classes, TikZ pictures, and bibliographies read from a .bibfile won’t match a real build (citations from a thebibliographylist are numbered). When you need a final, publication-ready PDF, export it from here or compile with a full TeX distribution such as TeX Live with latexmk, or Overleaf.
No. It's a fast, browser-based preview. Math is rendered with KaTeX and document structure with an HTML renderer, which is what makes it instant. Equation, section, figure, table and theorem numbers and \ref, \eqref and \cref links are worked out in the browser; page layout, packages beyond the common ones, and bibliographies from a .bib file need a real build. For byte-exact output, export to PDF or use a full TeX distribution.
No. Rendering happens entirely in your browser. Your LaTeX source never leaves your device, so the preview works even with sensitive or unpublished drafts. Only PDF export, when you click it, sends the source to the compile service.
Everything KaTeX supports (fractions, matrices, aligned environments, big operators, Greek letters, and most AMS-math), plus the macros you define with \newcommand or \def and the operators you declare with \DeclareMathOperator, in the preamble or in the body. Quantities written with siunitx (\qty, \SI, \num, \unit) are shown as plain text. Commands that need a full TeX engine or extra packages may not render.
Not for the preview: it is free and needs no signup. PDF export is free too and asks for a one-click Google sign-in.