Lazy Header Editor - Modify HTTP Headers

Add, modify, and remove HTTP request and response headers, redirect URLs, and manage multiple header profiles.

Introduction: Lazy Header Editor lets you add, modify, and remove HTTP request and response headers, and redirect URLs, right from your browser toolbar. It's built for developers and testers who need to simulate authentication tokens, test CORS configurations, override cache headers, or redirect requests without touching server code. What you can do with it: - Modify request headers add, set, append, or remove any header sent with outgoing requests (e.g. Authorization, X-Forwarded-For, custom API headers) - Modify response headers — control headers coming back from the server (e.g. Access-Control-Allow-Origin, Content-Security-Policy, cache-control headers) - Redirect URLs — send matching requests to a different URL, using either simple pattern matching or regex-based rewriting for more advanced redirects - Multiple profiles — create separate sets of header rules for different projects or environments (e.g. one profile for a staging API, another for local development), and switch between them instantly from the toolbar Per-profile URL filtering — restrict a profile's rules to only apply on specific sites, so your header changes don't leak into unrelated browsing - One-click enable/disable — a master toggle turns all header modification on or off instantly, with a badge indicator showing when it's active - Profile management — clone, rename, recolor, and delete profiles as your projects change - Export and import — save a profile as a JSON file to back it up or share your header setup with a teammate - Dark mode — matches your preferred theme How it works: The extension uses Chrome's declarativeNetRequest API (the standard, Manifest V3-compliant way to modify headers) to apply your rules only to the sites and requests you've configured. All your profiles and settings are stored locally on your device — nothing is sent to any external server, and the extension has no analytics or tracking of any kind. Who it's for: Web developers testing authentication flows, QA engineers verifying CORS and security header behavior, and anyone who needs to inspect or override how their browser sends and receives HTTP headers during development.