SetHeader

SetHeader lets you add, override, or remove HTTP request and response headers on requests matching URL patterns you define — useful for local development, API testing, and multi-tenant backends that require custom auth or tenant headers. Multiple profiles, all active at once — each profile is an independent set of headers, so you can run a tenant profile and a debug-logging profile simultaneously without them interfering. Multiple URLs per profile — each profile can list several URLs, wildcard or regex, each with its own on/off toggle and reorderable via ▲/▼. The profile's headers apply to any URL in the list that's currently active, so you don't need a separate profile just to reuse the same headers on a different site. Set, Append, or Remove — per header, choose whether to override a value, append to an existing one, or strip the header entirely. Toolbar badge shows exactly how many rules are currently active, so it's obvious at a glance whether SetHeader is doing anything right now. Export/Import lets you share profile configurations with teammates as JSON. All data — profiles, headers, values — is stored only in your browser's local storage on your own device. Nothing is ever transmitted anywhere by this extension. Questions or feedback? Email createapps360@gmail.com.