THorn HTTP: Intercept & Modify HTTP Requests by Cleber Silva

THorn HTTP lets you intercept and modify HTTP(S) traffic right in your browser. Everything runs locally: no account, no cloud, no analytics.

Rules
• Redirect Request: send a URL (or a pattern) to another URL, e.g. production → localhost
• Replace String: replace parts of URLs or hosts
• Query Param: add, change or remove query parameters
• Modify Headers: add, change or remove request and response headers
• Modify API Response: mock REST and GraphQL responses
• Modify Request Body: override request payloads
• Insert Scripts: inject JavaScript or CSS into pages
• Cancel Request: block requests
• Delay Network Requests: simulate slow APIs
• User-Agent: emulate other devices and browsers

Also
• Record the network traffic of a page and export it as HAR
• DevTools panel showing which rules ran on each request
• Import and export rules as JSON (Requestly exports are supported)
• Import from Charles Proxy, ModHeader, Resource Override and Header Editor
• Pause everything with one switch

Privacy
THorn HTTP stores your rules only in your browser and sends no data anywhere.

Open source
THorn HTTP is free software under the GNU AGPLv3, based on Requestly HTTP Interceptor. Source code: https://github.com/Thorn-http/thorn-http
"Requestly" is a trademark of its respective owner; THorn HTTP is not affiliated with or endorsed by BrowserStack Inc.