QuickHeader

Modify HTTP request and response headers right from your browser — no proxy, no server, no hassle.

QuickHeader lets you add, edit, or remove HTTP request and response headers right from your Chrome toolbar — no proxy, no server, no code changes. - Built for developers, QA engineers, and API testers who need to: - Inject an Authorization token to test an authenticated API endpoint - Bypass CORS while a local frontend talks to a remote API during development - Spoof a mobile or legacy User-Agent to see how a page responds - Force Cache-Control headers to debug caching issues - Simulate feature-flag headers your backend reads - Check what Googlebot would be served for SEO testing KEY FEATURES • Request & response header editing — set, remove, or toggle any header, per profile • Multiple named profiles with instant switching, so dev/staging/prod configs don't collide • URL scoping — restrict a profile to specific domains, or exclude specific domains • One-click CORS preset and a built-in User-Agent switcher with common device presets • Dynamic header values — {{timestamp}}, {{uuid}}, {{random_int}} for cache-busting or nonces • Recipe library — one-click starting points for common scenarios (disable CSP, force no-cache, legacy UA, and more) • Rule notes + "last triggered" / "unused in 30+ days" indicators, so you always know why a rule exists and whether it's still doing anything • Request log — see exactly which headers were changed on real requests, filterable by profile or domain, exportable per entry • Environment guardrails — tag a profile as "production" and any other profile marked "guardrail" will never fire its rules against that host, even if left active by mistake • Import/export your configuration as JSON to back it up or share it with a team • 100% local — no data leaves your browser; nothing is tracked or transmitted anywhere Install once. Test everything.