# [](https://khan.github.io/KaTeX/) [](https://travis-ci.org/Khan/KaTeX)
KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the web.
* **Fast:** KaTeX renders its math synchronously and doesn't need to reflow the page. See how it compares to a competitor in [this speed test](http://jsperf.com/katex-vs-mathjax/).
* **Print quality:** KaTeX’s layout is based on Donald Knuth’s TeX, the gold standard for math typesetting.
* **Self contained:** KaTeX has no dependencies and can easily be bundled with your website resources.
* **Server side rendering:** KaTeX produces the same output regardless of browser or environment, so you can pre-render expressions using Node.js and send them as plain HTML.
KaTeX supports all major browsers, including Chrome, Safari, Firefox, Opera, and IE 8 - IE 11. A list of supported commands can be on the [wiki](https://github.com/Khan/KaTeX/wiki/Function-Support-in-KaTeX).
## Usage
You can [download KaTeX](https://github.com/khan/katex/releases) and host it on your server or include the `katex.min.js` and `katex.min.css` files on your page directly from a CDN:
```html
```
#### In-browser rendering
Call `katex.render` with a TeX expression and a DOM element to render into:
```js
katex.render("c = \\pm\\sqrt{a^2 + b^2}", element);
```
If KaTeX can't parse the expression, it throws a `katex.ParseError` error.
#### Server side rendering or rendering to a string
To generate HTML on the server or to generate an HTML string of the rendered math, you can use `katex.renderToString`:
```js
var html = katex.renderToString("c = \\pm\\sqrt{a^2 + b^2}");
// '...'
```
Make sure to include the CSS and font files, but there is no need to include the JavaScript. Like `render`, `renderToString` throws if it can't parse the expression.
#### Rendering options
You can provide an object of options as the last argument to `katex.render` and `katex.renderToString`. Available options are:
- `displayMode`: `boolean`. If `true` the math will be rendered in display mode, which will put the math in display style (so `\int` and `\sum` are large, for example), and will center the math on the page on its own line. If `false` the math will be rendered in inline mode. (default: `false`)
- `throwOnError`: `boolean`. If `true`, KaTeX will throw a `ParseError` when it encounters an unsupported command. If `false`, KaTeX will render the unsupported command as text in the color given by `errorColor`. (default: `true`)
- `errorColor`: `string`. A color string given in the format `"#XXX"` or `"#XXXXXX"`. This option determines the color which unsupported commands are rendered in. (default: `#cc0000`)
For example:
```js
katex.render("c = \\pm\\sqrt{a^2 + b^2}", element, { displayMode: true });
```
#### Automatic rendering of math on a page
Math on the page can be automatically rendered using the auto-render extension. See [the Auto-render README](contrib/auto-render/README.md) for more information.
## Contributing
See [CONTRIBUTING.md](CONTRIBUTING.md)
## License
KaTeX is licensed under the [MIT License](http://opensource.org/licenses/MIT).
](https://khan.github.io/KaTeX/) [](https://travis-ci.org/Khan/KaTeX)
KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the web.
* **Fast:** KaTeX renders its math synchronously and doesn't need to reflow the page. See how it compares to a competitor in [this speed test](http://jsperf.com/katex-vs-mathjax/).
* **Print quality:** KaTeX’s layout is based on Donald Knuth’s TeX, the gold standard for math typesetting.
* **Self contained:** KaTeX has no dependencies and can easily be bundled with your website resources.
* **Server side rendering:** KaTeX produces the same output regardless of browser or environment, so you can pre-render expressions using Node.js and send them as plain HTML.
KaTeX supports all major browsers, including Chrome, Safari, Firefox, Opera, and IE 8 - IE 11. A list of supported commands can be on the [wiki](https://github.com/Khan/KaTeX/wiki/Function-Support-in-KaTeX).
## Usage
You can [download KaTeX](https://github.com/khan/katex/releases) and host it on your server or include the `katex.min.js` and `katex.min.css` files on your page directly from a CDN:
```html
```
#### In-browser rendering
Call `katex.render` with a TeX expression and a DOM element to render into:
```js
katex.render("c = \\pm\\sqrt{a^2 + b^2}", element);
```
If KaTeX can't parse the expression, it throws a `katex.ParseError` error.
#### Server side rendering or rendering to a string
To generate HTML on the server or to generate an HTML string of the rendered math, you can use `katex.renderToString`:
```js
var html = katex.renderToString("c = \\pm\\sqrt{a^2 + b^2}");
// '...'
```
Make sure to include the CSS and font files, but there is no need to include the JavaScript. Like `render`, `renderToString` throws if it can't parse the expression.
#### Rendering options
You can provide an object of options as the last argument to `katex.render` and `katex.renderToString`. Available options are:
- `displayMode`: `boolean`. If `true` the math will be rendered in display mode, which will put the math in display style (so `\int` and `\sum` are large, for example), and will center the math on the page on its own line. If `false` the math will be rendered in inline mode. (default: `false`)
- `throwOnError`: `boolean`. If `true`, KaTeX will throw a `ParseError` when it encounters an unsupported command. If `false`, KaTeX will render the unsupported command as text in the color given by `errorColor`. (default: `true`)
- `errorColor`: `string`. A color string given in the format `"#XXX"` or `"#XXXXXX"`. This option determines the color which unsupported commands are rendered in. (default: `#cc0000`)
For example:
```js
katex.render("c = \\pm\\sqrt{a^2 + b^2}", element, { displayMode: true });
```
#### Automatic rendering of math on a page
Math on the page can be automatically rendered using the auto-render extension. See [the Auto-render README](contrib/auto-render/README.md) for more information.
## Contributing
See [CONTRIBUTING.md](CONTRIBUTING.md)
## License
KaTeX is licensed under the [MIT License](http://opensource.org/licenses/MIT).