Header Override

Modify request headers, response headers, and cookies with local URL rules and profiles.

Header Override is an open-sourced developer tool for managing URL-scoped rules that modify request headers, response headers, request Cookie values, and response Set-Cookie values. Create rules from the extension popup, choose whether each rule affects outgoing requests or incoming responses, and scope each rule with Chrome's declarative URL filter syntax. Header Override can add request headers, add response headers, append request Cookie values, and add response Set-Cookie values with common cookie attributes such as Domain, Path, SameSite, lifetime, and Secure. Use profiles to keep separate rule sets for development, QA, demos, clients, or debugging sessions. Profiles can be activated from the popup, and selected profiles can be exported or imported as JSON when you need to move configurations between browsers or machines. Rules are saved locally in Chrome and applied automatically with Chrome's declarativeNetRequest API. Header Override does not use analytics, tracking, remote code, or external servers. Features: - Add custom request headers. - Add custom response headers. - Append request Cookie values. - Add response Set-Cookie values. - Configure response cookie attributes, including Domain, Path, SameSite, lifetime, Max-Age, and Secure. - Scope rules to specific URLs or URL patterns. - Group rules into local profiles. - Activate a profile for the current debugging workflow. - Import and export selected profile configurations. - Add optional comments to label or document each rule. - Enable, disable, add, and delete rules from the popup. - See the active applied rule count in the extension badge. - Local-only storage with no analytics, tracking, remote code, or external servers.