Interceptor - HTTP Proxy for Web Devs

Burp-style intercept (edit / forward / drop), HTTP history and repeater for testing your own web apps.

Interceptor is an HTTP intercepting proxy that lives in your browser. See, edit, replay and auto-tamper the requests your web app sends — without setting up a system proxy, installing certificates, or leaving the browser. It's built for web developers and security testers who need to know exactly what their app sends and receives, and to check how their backend responds to modified requests. WHAT YOU CAN DO • Intercept — Pause requests (and responses) and edit the raw method, path, query string, headers or body before they continue. Forward, drop, or forward-and-catch-the-response to tamper with what the page receives. • HTTP History — A live table of every request from the tab you're testing, with full request and response headers (including Cookie and Set-Cookie), bodies, status, timing and size. Filter by text or regular expression, pretty-print JSON, copy any request as a cURL command, and export everything as a HAR file. • Repeater — Hand-craft a raw request and fire it as many times as you like. What you type is exactly what goes on the wire — including Cookie, Origin, User-Agent and Sec- headers — with an "actual request sent" view so there are no surprises. • Auto mode — Force one or more fields to a fixed value on every outgoing request, automatically. This is purpose-built for price-tampering and server-side validation testing: set "amount" (and other payment fields) to 1 and instantly see whether your server re-validates the price or simply trusts the client. Turn it on for the current tab or for all tabs, right from the toolbar popup — no manual setup or attach step. It rewrites the field in query strings, form bodies, JSON (including deeply nested objects) and multipart forms, and logs every change. WHY IT'S DIFFERENT Interceptor uses the Chrome DevTools Protocol, so it can genuinely pause and modify live traffic — including request and response bodies — which ordinary content-blocking extensions cannot do. It runs entirely on your own machine: no account, no analytics, and no data ever leaves your browser. GREAT FOR • Debugging what your frontend actually sends to your API • Testing server-side validation of prices, quantities, IDs and permissions • Reproducing and tweaking API calls without a separate desktop tool • Capturing traffic as HAR for bug reports and reviews RESPONSIBLE USE This is a tool for testing applications you own or are explicitly authorized to test. Please do not use it to intercept or tamper with services you do not control. OPEN SOURCE Interceptor is free and open source (MIT). Read the code, file issues or contribute: https://github.com/user-github-me/interceptor