fxTeX Server API

In an image tag

The simplest use, and the most common: an equation is an <img>.

<img src="https://fxtex.codecogs.com/svg.image?1+\sin^2(x)" />
<img src="https://fxtex.codecogs.com/png.image?\int_a^b \frac{1}{x}\,dx = \ln\frac{b}{a}" />Copy

An SVG carries its own accessible label, so a screen reader announces the equation rather than the file name. For a PNG or GIF, give the <img> an alt.

Type

Format

The older .latex format — gif.latex?x^2, png.latex?x^2 — is still accepted, and behaves as .image.

Size, resolution and colour

These go at the front of the equation itself, in any order:

A colour is any CSS colour name — navy, crimson, white — or a hex value of three or six digits, with or without the #: \fg{c00}, \fg{#cc0000}. An unrecognised colour is ignored rather than treated as part of the equation.

<img src="https://fxtex.codecogs.com/png.image?\dpi{150}\bg{white}\fg{navy}\large e^{i\pi}+1=0" />Copy

Escaping an equation into a URL

Most LaTeX can be written into a URL as it is, and browsers will percent-encode it for you. Four characters need care, because they either end the query string or change meaning inside one:

The named forms (+, &space;, &hash;) are what the equation editor writes. They survive being pasted into HTML and through template engines that would mangle a %2B.

From code, encode the whole equation. In JavaScript:

const latex = '\\begin{pmatrix}a&b\\\\c&d\\end{pmatrix}';
const url = 'https://fxtex.codecogs.com/svg.image?' + encodeURIComponent(latex);Copy

Beware form encoders — Java's and Kotlin's URLEncoder, PHP's urlencode — which write a space as +. That reads here as a plus. Use rawurlencode in PHP, or replace + with %20 afterwards.

MathML

mathml returns markup rather than a picture, for inserting into a page yourself. It is accessible by default: the spoken form of the equation sits beside the <math>, which is hidden from screen readers so they announce one or the other, never both.

curl "https://fxtex.codecogs.com/mathml.image?x%5E2"Copy

<span class="cc-math fxtex"><math aria-hidden="true" class="fxtex" display="block" title="x^2">
  <msup><mi>x</mi><mn>2</mn></msup>
</math><span class="cc-speech">x squared</span></span>

The spoken text is hidden from sight by a stylesheet, which also makes small improvements to the browser's own MathML layout. Link it on any page that shows this markup — without it, the words appear as ordinary text beside the equation:

<link id="fxtex-style" rel="stylesheet" href="https://fxtex.codecogs.com/fxtex.css">Copy

If you would rather leave accessibility to the browser's own MathML support, ask for mathml_nospeech, which returns the bare <math> element.

The MathML is identical, character for character, to what fxTeX produces in the browser for the same input — the two share one converter.

JSON

Any type with the json format returns the result wrapped in an object, together with anything the converter could not understand:

https://fxtex.codecogs.com/svg.json?1+\sin^2(x)
https://fxtex.codecogs.com/png.json?1+\sin^2(x)
https://fxtex.codecogs.com/mathml.json?1+\sin^2(x)

{ "latex": {
    "type": "png",
    "equation": "x^2",
    "valid": true,
    "base64": "iVBORw0KGgoAAAANSUhEUgAAAD4AAAA1CAYAAAAZBliH...",
    "errors": []
} }

An error does not fail the request. The converter draws what it understood and lists what it did not, so one unknown command in a long equation costs you that command, not the equation. The errors list is the way to find out which of your equations use something we do not yet support — and it is a list we would like to see.

Fetching an SVG as JSON and turning it into an image:

fetch('https://fxtex.codecogs.com/svg.json?' + encodeURIComponent('1+\\cos^2(x)'))
  .then(r => r.json())
  .then(({ latex }) => {
    const img = document.createElement('img');
    img.src = 'data:image/svg+xml;charset=utf-8,' + encodeURIComponent(latex.svg);
    img.alt = latex.equation;
    document.body.append(img);
  });Copy

Status codes

What decides which of these you get is on Access and keys.

More

Access and keys — registering a domain, licence keys for apps, and request allowances.

Overview — what fxTeX Server is, and what changed from LaTeXRender.

fxTeX — the same converter running in the browser, with no request per equation.

fxEditor — letting your users write the equations in the first place.