Domain-matched HTTP request header modifier. Rules match by domain (case-insensitive) and apply to every tab. Session rules auto-clear on browser restart.
Chromium Β· MV3 Β· Header Modifier
π Free Features
Domain matching β Rules match by domain only (case-insensitive), paths ignored
Global rules β Empty Match URL applies to all requests
Rule system β Save multiple header configurations as rules
Auto re-apply β Enabled rules automatically re-apply on browser start
Request tester β Preview which rules match a URL and what headers they would set
Migrate from ModHeader / Header Editor β Import their exported JSON backups
Toolbar badge β Shows how many rules are currently active
Click the π Header icon in your toolbar to start
Privacy
β Zero data upload β all processing locally
β No analytics, no tracking
β Session rules auto-clear on browser close
β Permissions: storage, activeTab, sidePanel, declarativeNetRequestWithHostAccess, tabs β <all_urls> host access is required to modify request headers on the sites you choose