Browser developer tools

Code simulators

Run Python or build with HTML and CSS directly in your browser. No installation, account, or server upload required.

Python workspace

Python simulator

Write and run Python in a focused browser IDE with a real console, package support, and inline chart output.

  • Smart editorImports, APIs, and your variables
  • Packages and plots13 library families plus Matplotlib output

Front-end workspace

HTML & CSS simulator

Build a page with separate HTML and CSS editors, then inspect it instantly in a safe, responsive preview.

  • Live responsive previewMarkup, styles, scripts, and three viewport widths
  • Portable projectsLocal project manager and complete HTML downloads

Private browser workspaces

Test, save, and export

Both tools include autocomplete, local project management, and downloadable results without requiring an account.

01

Start immediately

Run the included example with no setup or sign-in.

02

Keep projects locally

Create and switch projects saved only in this browser.

03

Export the result

Download reusable Python or self-contained HTML files.

Python runs in a self-hosted browser worker. Front-end code renders in an isolated preview with network requests and parent-page navigation blocked.

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