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.
patina is an editing tool for writing you are allowed to produce with AI assistance: it changes wording, never your claims, numbers, or causation. It is not an authorship detector and not a tool for evading one — see the ethics policy.
Free
$0
- Browser playground
- 20 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
- Premium AI engine
- 100 rewrites / month
- Up to 20,000 characters each
- 50,000 characters / month total
Pro is a licensed hosted tier. Enter your license key in Pro mode to use it in this browser session; it is never saved. The monthly rewrite count and the monthly character total are separate budgets — whichever runs out first ends the month, so long documents consume the character budget well before 100 rewrites.
Paste your own and see
Drop an AI-sounding draft into the box above. No code, no key.