Make it sound human
Paste AI-sounding text — patina rewrites it naturally. KO·EN·ZH·JA.
how to use
Three steps
1 · Paste
Drop in your AI-sounding draft. No code, no key.
2 · Rewrite
patina clears ~160 patterns and rewrites it naturally.
3 · Verify
Check MPS, fidelity, and the AI signal (before → after).
samples
Before and after
benchmark
Numbers, in the open
A deterministic suspect-zone benchmark on a checked-in fixture corpus — auditable, not an authorship test.
- 100%
- overall accuracy 95% CI 92.7–100%
- 49
- fixtures AI vs. natural, labeled
- 4
- languages KO · EN · ZH · JA
- 0
- false positives at the 1% FPR budget
| lang | fixtures | accuracy | 95% CI | F1 |
|---|---|---|---|---|
| EN | 13 | 100% | 77.2–100% | 1.00 |
| JA | 12 | 100% | 75.8–100% | 1.00 |
| KO | 12 | 100% | 75.8–100% | 1.00 |
| ZH | 12 | 100% | 75.8–100% | 1.00 |
Measured on 49 deterministic fixtures as a regression gate — not a claim of generalization to new models, genres, or edited AI text, and not an authorship verdict.
Read the full report →pricing
Simple pricing
Try it free in the browser, bring your own key, or go Pro for higher limits on Claude Sonnet 5.
Free
$0
- Browser playground
- 5 rewrites / day
- Up to 4,000 characters
- KO · EN · ZH · JA
API
Your key
- Bring your own provider key
- Up to 20,000 characters
- Key stays in your browser
- Never stored or logged
Pro
$9.99/mo
- Claude Sonnet 5
- 200 rewrites / day
- Up to 20,000 characters
- 1,000,000 characters / month
Pro is a licensed hosted tier. Enter your license key in Pro mode to use it in this browser session; it is never saved.
Paste your own and see
Drop an AI-sounding draft into the box above. No code, no key.