"I built a Python compiler that runs in browser using WebAssembly"

"I recently built PyPlayground —
a free online Python compiler.

The interesting part is it runs
Python 3.12 entirely in the browser
using Pyodide WebAssembly — no
server required!

How it works:
• User writes Python code
• Pyodide compiles it to WASM
• Runs natively in browser
• Output shown instantly

Tech stack:
• Next.js for frontend
• Pyodide for Python runtime
• Netlify for hosting

Try it here:
Pyplayground

Would love feedback from
the dev community! 🙏

Comments

[Frank]

This is super cool! How did you manage the memory footprint of the Python runtime within the browser'

[shrirang]

"Great question!

Pyodide's memory footprint is
actually one of its interesting
trade-offs:

Initial load: ~8MB download
(Python runtime + standard library)

Runtime memory: ~50-100MB
in browser RAM while active

How I handle it:
→ Lazy loading — Pyodide only
loads when user clicks Run
→ Single instance — load once,
reuse for all executions
→ Browser manages cleanup
automatically

The good news:
After first load it's cached by
the browser — so repeat visitors
get instant startup!

For a beginner tool the trade-off
is worth it — no server cost at all.