HttpMockBench

About

HttpMockBench — API client, HTTP logger & request mocker built for developers who value privacy.

One DevTools-native extension to test APIs, intercept HTTP traffic in real-time, and mock any request — without touching your code, without installing a proxy, without sending your data anywhere.

API CLIENT
Send HTTP requests with full control over method, headers, body and authentication (Bearer, Basic, API key). Save requests into collections, switch between environments with {{variable}} placeholders, import/export cURL commands, and browse your full request history.

HTTP LOGGER (DevTools)
Open DevTools and get a real-time feed of every request made by the current tab — URL, method, status code, timing, request and response headers, and body. Click any entry to inspect it in detail.

REQUEST MOCKER
Intercept fetch and XHR calls at the browser level — no proxy, no code change. Return custom fixed responses, set any status code, inject latency, or redirect URLs to another target. Rules are matched by URL pattern and HTTP method.

FREEZE TO MOCK
See a response in the HTTP Logger you want to reproduce? One click prefills a mock rule with its exact status, headers and body. Activate immediately — no copy-paste, no manual setup.

FREE TIER
• API Client with collections, environments & history
• Real-time HTTP Logger in DevTools
• Request Mocker (up to 10 rules)
• Redirect rules
• Freeze to Mock
• cURL import & export

PRO TIER
• Unlimited mock rules, collections, environments & history
• Coming soon: Postman/Insomnia/Bruno import, regex URL matching, stateful mocking, dynamic response templates, pre/post request scripts

PRIVACY FIRST
Zero tracking. Zero analytics. Zero telemetry. Your requests never leave your machine — no relay server, no cloud sync, no external calls. Everything runs locally inside your browser.

PERMISSIONS EXPLAINED
- Storage: saves your rules, collections, environments and history locally (IndexedDB)
- WebRequest: observes requests made by the current tab to power the HTTP Logger (read-only, never modifies network traffic at this level)
- DeclarativeNetRequest: handles redirect rules natively via the browser engine
- Scripting: injects the interceptor into pages (MAIN world) to mock fetch and XHR calls
- All URLs: mocking and logging can apply to any domain — the extension needs to work everywhere

No account required to get started. Pro upgrade available inside the extension.

Questions or bugs? https://github.com/valentinconan/httpmockbench-site/issues
Website: https://httpmockbench.com