Write LaTeX math notation and see it typeset instantly
KaTeX typesets LaTeX math notation in the browser. You get the rendered formula without installing a TeX distribution, and the file keeps the notation you typed.
How to write it
Inline math
Area: $S = \pi r^2$A single $ on each side puts the formula in the flow of the sentence, with the line height kept close to the surrounding text.
Display math
$$
\int_{0}^{\infty} e^{-x^2}\,dx = \frac{\sqrt{\pi}}{2}
$$Double $$ gives the formula a line of its own. Tall symbols such as integrals and fractions are set more legibly this way.
What this editor gives you
Typeset while you type
The formula appears as soon as the notation is complete. There is no separate preview pane to switch to.
Typeset inside your browser
KaTeX runs locally. Your formulas are not sent to a server to be rendered.
The file keeps the notation
What is saved is the $-delimited LaTeX you wrote, so any other tool that understands the same notation can read it.
Frequently asked questions
Is all of LaTeX supported?
Everything KaTeX supports. Math notation is broadly covered, but document-level LaTeX — macros and packages that typeset a whole paper — is out of scope.
Do I need a TeX distribution?
No. Typesetting happens in the browser.
Can I take my formulas elsewhere?
Yes. The file contains the `$`-delimited LaTeX notation itself, so any tool that reads the same notation can open it unchanged.
You can try this syntax right now.
Open the editor