Python 3 in the browser

Usage no npm install needed!

<script type="module">
  import brython from '';



Brython (Browser Python) is an implementation of Python 3 running in the browser, with an interface to the DOM elements and events.

Here is a simple example of an HTML page running Python:


            <script type="text/javascript" src="/path/to/brython.js"></script>

        <body onload="brython()">

            <script type="text/python">
            from browser import document, alert

            def echo(event):

            document['mybutton'].bind('click', echo)

            <input id="zone"><button id="mybutton">click !</button>



To use Brython, all there is to do is:

  1. Load the script brython.js. If you want to use modules from the standard library, also load brython_stdlib.js
  2. Run the function brython() on page load, like <body onload=brython()>.
  3. Write Python code inside tags <script type="text/python"> or linking it.

Main features

Brython supports most of the syntax of Python 3, including comprehensions, generators, metaclasses, imports, etc. and many modules of the CPython distribution.

It includes libraries to interact with DOM elements and events, and with existing Javascript libraries such as jQuery, 3D, Highcharts, Raphael etc. It supports lastest specs of HTML5/CSS3, and can use CSS Frameworks like Bootstrap3, LESS, SASS etc.

Test Brython online

If you want to test Brython online you can visit the following:

Gallery of examples

There is a gallery of examples where you can see simple and advanced examples using vanilla Brython or interacting with other javascript libraries.


Documentation is available on the official site. You can read the docs in English, French and Spanish.

Curious about how Brython works ?

Community (questions, feedback, issues, new features, ...)

There is a main mailing list in English.

If you find a bug/issue or do you want to see a new feature in Brython, please, open a new issue.