Network Interceptor

Intercept, mock, redirect, block, and modify network requests for development and testing.

Network Interceptor gives developers full control over network requests directly in the browser. Set up rules to mock, redirect, block, delay, or modify requests — without touching your backend or configuring a proxy. ── RULE TYPES ────────────────────────────────────────── Mock Return a custom response body and status code for any fetch or XHR request. Redirect Transparently forward a request to a different URL, preserving the original method and headers. Block Cancel matching requests outright. Delay Slow down requests by a configurable number of milliseconds to simulate latency. Modify Headers Add, set, or remove request and response headers on matching requests. Modify Query Params Add, replace, or remove URL query parameters without editing your source code. Redirect JS Serve a local or alternate script in place of a remote JavaScript file. ── MATCHING OPTIONS ──────────────────────────────────── Match URLs by exact string, contains, wildcard (*), or full regex. Filter by HTTP method (GET, POST, PUT, DELETE, etc.) or match any. ── HOW IT WORKS ──────────────────────────────────────── Rules are applied in real time — no page reload required after toggling. A subtle on-page toast shows which rules fired and against which URL, so you always know what was intercepted. ── USE CASES ─────────────────────────────────────────── • Mock API responses during frontend development • Test error states (404, 500) without backend support • Simulate slow network conditions • Override feature flags or A/B test payloads • Strip or inject authentication headers • Redirect production API calls to a local dev server No external servers. No data leaves your browser.