If you use
--fingerprint, this one changes what the browser reports.
playwright_context_kwargs mapped the user agent, the locale, the timezone
and the screen onto the browser context and ignored deviceScaleFactor,
which the fingerprint API returns beside them.
Measured 2026-09-11 against the live API and a live browser:
| fingerprint says | browser reported, before | |
|---|---|---|
| user agent | Chrome/146 on Windows | ✅ same |
| locale | nl-NL |
✅ same |
| timezone | Europe/Amsterdam |
✅ same |
| screen width | 1536 | ✅ same |
| devicePixelRatio | 1.25 | 1 ❌ |
That is the mismatch the flag exists to prevent, on an axis any
fingerprinter reads for free and for nothing: the paid identity said one
thing and the browser said another, on every run, silently.
Playwright takes it as its own context option, so the fix is to pass it.
Verified in a live browser both ways and pinned in the offline suite.
Found while auditing a new sibling repo against the family notes — all
five repos in this family had it.
🤖 Generated with Claude Code