Code Refactoring
Commercial use OK
380+ models
No watermark
No sign-up needed
Model:
+ GPT-5, Claude, Gemini
Paste code and get a refactored version — cleaner names, extracted functions, idiomatic patterns, removed duplication. Pick a refactor goal to steer priorities. Returns a side-by-side diff plus a per-change rationale. Works on 16+ languages.
Changes + rationale
Advanced options
Result
Tokens running low.
Get More Tokens
❤️ Love Free.ai? Tell your friends!
Sign up to get a referral link and earn 25,000 tokens per friend.
Want more?
Sign up free for 5K tokens/day + 10K bonus
Sign Up Free
Processing your request...
Refactor and optimize code with free AI. Cleaner, faster, more maintainable code.
How to Use Code Refactoring
1
Enter your input
Type text, upload a file, or describe what you want. No account needed.
2
Click generate
Our AI processes your request in seconds using the best open-source models.
3
Download & share
Download, copy, or share your result. Free for personal and commercial use.
Use this tool via API
Automate this tool from your own code. OpenAI-compatible REST endpoint, Bearer-token auth, no extra SDK required. Token costs match the web interface.
curl -X POST https://api.free.ai/v1/chat/ \
-H "Authorization: Bearer sk-free-..." \
-H "Content-Type: application/json" \
-d '{"model": "qwen-coder", "messages": [{"role": "user", "content": "Write a Python function that reverses a string."}]}'Code Refactoring — FAQ
Paste code, pick a refactor goal (readability / modernize / types / tests-first / performance / DRY / SOLID / async / error handling), get back a refactored version plus a per-change rationale and a side-by-side diff.
Review DIAGNOSES (severity-graded findings). Refactor FIXES — it gives you the rewritten code. Use Review to decide whether to refactor; use Refactor to do it.
Yes — that's the contract. "Keep public API signatures" and "Don't break existing tests" are checked by default; the model must produce a Behavior-preservation statement confirming or flagging any semantic change.
Readability (clearer names, smaller fns), Modernize (current idioms + stdlib), Type safety (annotations), Tests-first (pure + DI), Performance (complexity + allocation), Remove duplication, SOLID, Async-ify, Error handling.
No — always read the diff before pasting back. The model is strong at idiomatic rewrites but can occasionally change subtle behavior in edge cases. Run your tests; the diff view makes review fast.
Qwen 3 Coder is the default — fast and correct on ~95% of refactors. DeepSeek R1 for deep-reasoning multi-hundred-line rewrites. Premium Claude Sonnet 4 / GPT-5 for whole-file rewrites on complex business logic.
JetBrains refactors are deterministic (rename, extract method, move class). Free.ai Refactor is GENERATIVE — it rewrites code in ways IDE refactors can't, like idiomatic modernization or end-to-end testability. Use both.
Copilot edit is inline-IDE, single-file, fast. Free.ai Refactor is browser-based and gives you a structured rationale + diff + follow-ups list, plus 9 goal modes to pick from. Copilot for flow; Free.ai for thinking about the refactor.
Side-by-side with removed lines in red (--), new lines in green (+), unchanged lines in gray. Click Diff on the result panel to toggle; switch to Refactored for clean new code, Original for your input.
Yes — click Original in the view switcher, or "Refactor another" to start fresh. Code Refactoring never auto-applies changes; you paste back what YOU choose.
Code is sent to the model, processed, and discarded. Not stored, not used for training. For max privacy pick Qwen 3 Coder (self-hosted on our GPUs — never leaves our servers).
Yes — POST to /v1/chat/ with a system prompt describing your refactor goal + constraints and the code as the user message. See /api/ for the full spec.
How would you rate this tool?