A LaTeX equation editor with instant preview
This LaTeX equation editor renders what you type as you type it, using the KaTeX engine, so you can build fractions, roots, integrals, sums, Greek letters and matrices without guessing at syntax and recompiling a document. A palette inserts the common constructs at the cursor, a template menu gives you well-known formulas to adapt, and any error is explained in plain words with the position where KaTeX stopped.
When the equation looks right, download it as a crisp PNG (2×, 3× or 4× scale, transparent or solid background) for slides, Word documents, Google Docs or a forum post; copy the LaTeX wrapped in $$…$$ for Markdown, Jupyter or Overleaf; copy MathML for accessible web pages; or copy a share link that re-opens the same equation here.
The renderer is loaded from a public CDN and runs in your browser; nothing you type is sent to a server.
How to use the LaTeX Equation Editor
- Type or paste LaTeX into the LaTeX box — for example
\frac{a}{b}or\int_0^1 x^2\,dx. The preview updates after each keystroke. - Use the palette buttons to insert a fraction, root, sum, integral, Greek letter or matrix at the cursor. Select some text first and it is placed inside the first pair of braces.
- Pick a formula from Templates if you want a starting point such as the quadratic formula or a 2×2 inverse.
- Switch between Display (centred, large operators) and Inline (compact, for use inside a sentence) and adjust the preview size.
- If a red message appears, read it: it names the missing brace or unknown command. The last good rendering stays in the preview until the error is fixed.
- Press Download PNG, or use the copy buttons for LaTeX,
$$…$$, MathML or a share link.
LaTeX Equation Editor features
Live KaTeX rendering
KaTeX 0.16 (MIT licence) renders synchronously, so even long equations with matrices and aligned environments appear within milliseconds.
Symbol palette and templates
Structure, big operators, relations, arrows, set symbols, 20 Greek letters, matrices, cases, accents, bold and blackboard letters, plus 13 ready-made formulas.
PNG export with real fonts
The rendered HTML is serialised into an SVG with the KaTeX fonts embedded, then drawn to a canvas at 2–4× resolution — the PNG looks exactly like the preview, with an optional transparent background.
MathML and Markdown copies
One click gives you MathML (with the correct namespace) for HTML pages and screen readers, or the LaTeX wrapped as $$…$$ or $…$.
Shareable links
The equation and mode are encoded in the page address so a colleague or student opens exactly what you see.
Clear error messages
Parse errors from KaTeX are shown with the character position, which is far quicker than hunting through a LaTeX compiler log.
LaTeX syntax cheat sheet
Most of what you need fits in a short table. Braces {} group arguments; a single character does not need them (x^2) but anything longer does (x^{10}).
| What you want | LaTeX | Notes |
|---|---|---|
| Fraction | \frac{a}{b} | \dfrac forces display size inline |
| Root | \sqrt{x}, \sqrt[3]{x} | optional index in square brackets |
| Powers and indices | x^{2}, a_{ij} | combine: x_i^2 |
| Sum, product, integral | \sum_{i=1}^{n}, \prod, \int_a^b | limits go in sub/superscripts |
| Greek letters | \alpha \beta \theta \pi \Omega | capitalise for upper case |
| Scaled brackets | \left( \frac{a}{b} \right) | every \left needs a \right |
| Matrix | \begin{pmatrix} a & b \\ c & d \end{pmatrix} | bmatrix for square brackets, vmatrix for determinant bars |
| Text inside math | \text{if } x > 0 | keeps normal spacing and upright letters |
| Thin space / wide space | \, / \quad | use \, before dx |
Using the exported equation elsewhere
- Word, PowerPoint, Google Slides: download the PNG at 3× or 4× with a transparent background and insert it as a picture; it stays sharp when scaled.
- Markdown, Jupyter, Obsidian, GitHub: copy with
$$…$$; most Markdown renderers accept that delimiter for display math. - HTML pages: paste the MathML into the page — modern browsers render it natively, and screen readers can read it.
- Overleaf or any LaTeX document: copy the plain LaTeX into an
equationoralignenvironment. - Need a graph of the function you have just written? Open the function grapher; for determinants and inverses the matrix calculator prints its results as LaTeX you can paste back here.
Limits of the editor
KaTeX supports the maths subset of LaTeX, not full documents: there is no \usepackage, no TikZ pictures and no custom macros beyond \newcommand inside the input. Chemistry notation (\ce) and some rarely used AMS commands are not loaded. Very wide equations scroll horizontally in the preview and export at their full width. The PNG export relies on SVG foreignObject rendering, which works in current Chrome, Edge, Firefox and Safari; if a browser blocks it you can still copy the LaTeX or MathML.
LaTeX Equation Editor FAQ
Is this LaTeX equation editor free to use?
Yes. It runs entirely in your browser with the open-source KaTeX library; there is no account, limit or watermark on the PNG export.
How do I write a fraction in LaTeX?
Use \frac{numerator}{denominator}, for example \frac{a+b}{2}. The “a⁄b” palette button inserts the command and places the cursor in the first brace.
Why does my equation show a parse error?
The most common causes are an unmatched brace, a \left without a matching \right, or an unknown command (KaTeX supports the standard maths commands but not every package). The message tells you where KaTeX stopped reading.
Can I export the equation as an image?
Yes. Download PNG renders the preview at 2×, 3× or 4× scale with a transparent, white or dark background, embedding the KaTeX fonts so it matches the preview exactly.
What is the difference between display and inline mode?
Display mode centres the equation on its own line and uses large limits on sums and integrals, like $$…$$ in LaTeX. Inline mode is compact for use inside a sentence, like $…$.
Does the share link upload my equation?
No. The LaTeX is encoded in the part of the address after #, which browsers never send to the server; whoever opens the link renders it locally.