Header Override

Override request headers on API calls, with an on/off switch for every rule

Header Override adds, replaces, or removes request headers on the API calls your pages make. It's built for developers and testers who need to send an auth token, an environment flag, or a custom header without changing any code. FEATURES • Set any request header: x-token, Authorization, X-Env, feature flags, and more • Remove headers you don't want sent, such as Cookie • Turn each rule on or off with its own switch • Pause every rule at once with the master switch • Limit a rule to specific domains (subdomains and all ports included), or apply it everywhere • Header values are masked by default, so tokens stay hidden while you share your screen • The toolbar badge shows how many rules are active • Changes take effect immediately, with no Apply button and no page reload needed for new requests HOW TO USE 1. Click the Header Override icon in the toolbar 2. Click "Add" and enter a header name and value 3. Optionally enter the domains the rule should apply to, such as api.example.com or localhost 4. Use the switches to turn rules on or off as you work Rules apply only to fetch and XHR requests, so page loads, images, and other resources are left untouched. PRIVACY All rules, including header values, are stored locally in your browser and never leave your device. The extension uses Chrome's built-in declarativeNetRequest API, so it never reads the content of your requests or responses.