Cloudflare Python Workers are now generally available
- ID
- 27007
- Status
- summarized
- Published
- 22 Sep 2026, 6:25 AM
- Fetched
- 22 Sep 2026, 6:38 AM
- Provider
- Simon Willison
- Category
- developer-ai
- Original URL
- https://simonwillison.net/2026/Sep/21/cloudflare-python-worker/
- Source URL
- https://simonwillison.net/atom/everything/
Summary
- Score
- 6.5
- Created
- 22 Sep 2026, 6:38 AM
- Tags
- Audience
- developersvibe_coderssaas_founders
What happened
Cloudflare's Python Workers are now generally available after a two-year preview, making Python a first-class language on their edge platform. Python code runs compiled to WebAssembly via Pyodide inside the V8-based workerd runtime, which means multiprocessing and threading are non-functional. Local development uses the pywrangler tool (published as workers-py on PyPI) which runs a 123MB workerd binary simulating the full stack locally.
Why it matters
If you've been waiting for Python on Cloudflare Workers to stabilize before deploying, GA means you can now use it in production with confidence—but you must design around the no-threading/no-multiprocessing constraint, which rules out CPU-bound parallelism and many standard Python libraries that rely on either. The Pyodide-in-WASM approach also means pure-Python packages work but native C extensions may not, so validate your dependency tree before committing.
Discussion angle
Compare the Pyodide-in-WASM constraint set against alternatives like FastAPI on a traditional VPS or Lambda—when does edge Python actually win, and when does the no-threading limitation make it more trouble than it's worth?