Initializing Python Environment

Lifting off into Mastery...

Master the IDE

Write Code: Write Python code in the editor or upload a file. Initialize packages if needed.
Run & Output: Click "Run Code" or press Ctrl/Cmd+Enter. Results and errors appear in the Output Console below.
Keep Learning: Head to Academy for structured courses or Tutorial Lab for hands-on practice.

Core Features

Recipe Library Code Snapshot Social Share Change Layout Multi Tab Support Time Travel History Upload/Download Package Manager Python Academy Tutorial Lab Find & Replace Code Folding Live Syntax Checker Interactive 3D Plots
🔒 Runs 100% in your browser · Your code never leaves your device · Completely private & secure

PythonMastery

Code Python. No setup. Just mastery.

Loading... Runs Locally
Tutorial Lab Academy
Tutorial Lab Academy
main.py
📦 Package...
Tip: To see Seaborn charts, make sure you call plt.show() just like in Matplotlib!
Tutorial Lab Academy
Output Console
Output will appear here...
main.py
pythonmastery.io

Free Online Python IDE — Run Python 3.13 in Your Browser, No Installation Needed

PythonMastery is a free, browser-based Python IDE powered by Pyodide 0.28 (WebAssembly), running Python 3.13 — the latest stable release. Write and execute Python code instantly — no pip install, no setup, no account required. Everything runs 100% locally on your device. Your code never reaches our servers.

Why use PythonMastery?

  • Zero setup — Open your browser, start coding Python immediately. No download, no install.
  • Privacy first — Code runs locally via WebAssembly. Nothing is sent to any server.
  • No login required — No account, no subscription, no email. Just open and code.
  • Professional code editor — CodeMirror 6 with syntax highlighting, code folding, find & replace, bracket matching, auto-indent, and live syntax checking.
  • Full library support — Install NumPy, Pandas, Matplotlib, Scikit-learn, SciPy, Seaborn, and hundreds more directly in the browser via micropip.
  • Interactive data visualization — Create charts, plots, and interactive 3D figures with Matplotlib. Pan, zoom, and rotate right in the browser.
  • 3 theme modes — Dark, Light, and Eye Saver themes with matched editor, console, and toolbar styling.
  • Mobile friendly — Full IDE experience on phones and tablets with native touch selection, responsive layout, and optimized controls.
  • Learn Python online — Structured courses in Python Academy, hands-on exercises in Tutorial Lab, and a Recipe Library of ready-to-run code templates.
  • Session restore — Your code, open tabs, and progress are saved locally. Come back after a day, a week, or a month — everything is exactly where you left it.
  • Time Travel history — Every run is saved as a snapshot. Made a mistake? Roll back to any previous version of your code with one click.
  • Share your code — Generate a shareable link that encodes your code in the URL. No server storage needed.

Frequently Asked Questions

Can I run Python in a browser without installing anything?
Yes. PythonMastery uses Pyodide — a WebAssembly port of CPython — to run Python 3.13 entirely in your browser. No installation of Python, pip, or any tool is needed.
Is my Python code private and secure?
Completely. Your code executes locally on your machine and is never transmitted to any server. We have no access to what you write or run.
What Python libraries are available online?
You can install and use NumPy, Pandas, Matplotlib, Scikit-learn, SciPy, Seaborn, Pydantic, and hundreds of other pure-Python packages directly in the browser via micropip.
Can I create charts and visualizations in the browser?
Yes. Matplotlib works fully in PythonMastery — including interactive 3D plots you can pan, zoom, and rotate. Static charts render inline in the console, while interactive figures open in a dedicated section with a full toolbar.
Does it work on mobile devices?
Yes. PythonMastery is fully responsive and works on phones and tablets. The editor supports native touch selection with drag handles, and the layout adapts to portrait and landscape orientations.
Is this Python online compiler free?
Yes, PythonMastery is completely free, supported by non-intrusive ads. No paid plans, no feature paywalls.
Can I learn Python for free here?
Yes. Python Academy offers structured learning paths from beginner to advanced, covering Python fundamentals, data science, machine learning, and AI — all free, all in the browser.