Header Editor — HTTP Request Header Manager

Add custom HTTP request headers to any site. Inject Authorization tokens, CORS headers, or... | Not affiliated with Anthropic, PBC.

Header Editor is a lightweight Chrome (MV3) tool for developers, QA engineers, and API testers who need to tweak outgoing HTTP request headers. Create rules to set, append, or remove request headers — an Authorization bearer token for local testing, a custom debug header, or an API-version pin — and target each rule to a specific URL pattern. Features: - Set, append, or remove HTTP request headers per rule - Target rules by URL pattern (declarativeNetRequest, MV3) - Enable / disable each rule individually - Add / edit / delete rules from a simple popup - Rules stored locally on your device Scope (so you know before you install): - Request headers only — it does not read response bodies or edit response headers - No redirect, block, or URL rewriting Free: up to 5 rules. Pro: unlimited rules. Available in English and Japanese.