Network Layer
HTTP Headers: The First Layer of Your Fingerprint
Before canvas or WebGL runs, your headers already reveal your OS, browser build, locale, device class, and even hardware hints via Client Hints. Detection systems score consistency across every header.
UA + Client HintsAccept-* surfacesIP/Geo correlation
Headers that fingerprint you
- User-Agent: Baseline OS/browser. Must align with GPU, fonts, screen size.
- Client Hints (
Sec-CH-UA, platform, model, full-version): Modern detectors prefer these over UA; mismatches are fatal. - Accept-Language / Accept: Locale + content preferences; inconsistent with IP ≈ proxy/VPN flag.
- Referer / Origin: Reveal cross-site context and automation if malformed.
- Connection / Upgrade-Insecure-Requests: Older automation defaults betray bots.
Consistency rules
- UA OS ↔ Client Hints platform ↔ reported screen resolution.
- GPU/vendor from WebGL must exist on the claimed OS/device class.
- Fonts set should match locale and OS family (Windows vs macOS vs Android).
- IP geolocation should not contradict Accept-Language and timezone.
Common failure patterns
- Missing Client Hints on Chromium 110+ (automation defaults).
- Desktop UA with mobile viewport or Android fonts.
- Proxy IP in US, but Accept-Language = ru-RU and timezone = Asia/Novosibirsk.
- JA3/TLS shows Python/Go fingerprint while headers claim Chrome.
Mitigation Strategy
- Adopt Client Hints fully; partial hints look fake. Mirror Chromium defaults.
- Template profiles: choose a real device persona and keep all headers aligned to it.
- Regenerate TLS/JA3 alongside headers when rotating identities.
- Localize: align Accept-Language, timezone, IP geolocation, and fonts.
- Test after changes with automated checks, not just manual eyeballing.
Use the HTTP Headers Test to capture your live headers, then cross-check with TLS Fingerprint and IP/Geo for alignment.
Audit your headers now
Inspect UA + Client Hints, detect leaks, and export results for automation tuning.