# Moq - Mock API Requests > Mock HTTP requests with custom responses, status codes, delays, and headers. Perfect for development, testing, and debugging. Canonical page: [https://chrome-stats.com/d/moq-mock-api-requests](https://chrome-stats.com/d/moq-mock-api-requests) ## Overview - **ID:** `moq-mock-api-requests` - **Platform:** Firefox - **Type:** Firefox add-on - **Status:** Available - **Publisher:** Pavel Shpakovich - **Category:** web-development - **Daily users:** 13 - **Version:** 2.15.7 - **Last updated:** 2026-06-29 - **First published:** 2026-02-28 - **Size:** 393 KB - **Data as of:** 2026-09-08 - **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/moq-mock-api-requests/) - **Website:** [https://github.com/PavelShpakovich/mock-ext](https://github.com/PavelShpakovich/mock-ext) - **Privacy policy:** [https://addons.mozilla.org/firefox/addon/moq-mock-api-requests/privacy/](https://addons.mozilla.org/firefox/addon/moq-mock-api-requests/privacy/) ## Description Moq - Powerful API Mocking for Chrome DevTools Moq is a developer tool that intercepts and mocks HTTP requests directly in your browser, eliminating the need to modify backend code or wait for API changes during frontend development. WHY INSTALL MOQ? ✓ Speed Up Development - Test different API responses instantly without backend changes or server restarts ✓ Isolated Testing - Work offline or test edge cases (errors, timeouts, specific data) that are hard to reproduce ✓ No Code Changes - Mock requests at the browser level without touching your application code ✓ Real Time Control - Enable/disable mocks on-the-fly, perfect for comparing real vs mocked responses KEY FEATURES → Client-Side Interception Captures fetch() and XMLHttpRequest before they reach the network → Full Response Control Set custom status codes (200, 404, 500), response bodies, headers, and delays → Proxy Rules Route matching requests through a custom proxy target instead of returning a mock response • Redirect requests to any base URL (e.g. staging, local server) • Optional path rewrite with from/to pattern (plain string or regex) • Attach JavaScript response hooks to transform proxied responses • Conflict detection warns when a proxy rule overlaps with a mock rule • Hit counters track how many times each proxy rule is triggered • Import/Export proxy rules independently from mock rules → Response Hooks with JavaScript Write code to transform responses dynamically (both mock and real) • Toggle hooks on/off without deleting code • Comprehensive validation catches undefined variables and syntax errors • Available globals: response, request, helpers (uuid, timestamp, random data) → Two Response Modes • Mock Mode - Return configured mock response with your custom data • Passthrough Mode - Forward request to real server and transform response with JavaScript hook → Dynamic Variables Generate unique data with {{timestamp}}, {{uuid}}, {{random_number}}, {{random_string}} in responses → Request Recording & Logging Record and inspect actual network traffic, create mocks from real responses with one click → Smart Organization Group rules into folders, search and filter, bulk enable/disable, hit counters show usage • Compact and detailed view modes for both Rules and Proxy tabs → Rule Validation & Warnings Automatic detection of invalid regex, JSON errors, overlapping rules, and unused rules → Import/Export with Preview Share rule configurations with merge or replace modes, validate before importing → Multi-Monitor Support Open in standalone window or DevTools panel, full state synchronization → Dark/Light Theme System preference detection with manual override → CORS Auto-Fix Automatically inject CORS headers to bypass cross-origin restrictions → Multi-Language Full English and Russian translations USE CASES & BENEFITS FOR FRONTEND DEVELOPERS: • Test different API responses without backend changes • Redirect API calls to a local or staging server with Proxy Rules • Work offline or before backend APIs are ready • Validate error handling with custom error responses • Test loading states with configurable delays FOR QA ENGINEERS: • Simulate edge cases that are hard to reproduce • Test timeout scenarios and network failures • Validate UI with specific data combinations • Automate testing with exported rule configurations FOR DEBUGGING: • Modify production API responses locally for troubleshooting • Proxy requests to a different environment without changing application code • Compare real vs mocked responses side-by-side • Track request/response patterns with hit counters • Organize test scenarios into folders for different features PRIVACY & SECURITY ✓ No data collection ✓ No external servers ✓ All data stored locally in your browser ✓ Open source and transparent GETTING STARTED
  1. Open Chrome DevTools (F12)
  2. Click the "Moq" tab
  3. Create your first mock rule with URL pattern matching
  4. Enable recording to capture real requests
  5. Click "Mock This" on any logged request to create a rule instantly
  6. Use Proxy Rules to redirect requests to a different server without changing your code
Perfect for frontend developers, QA engineers, and anyone who needs to test API integrations without modifying backend code or waiting for server changes. All data stays local - no external servers, no data collection, complete privacy. ## Rankings - #29,063 — Overall - #15 — mock - #31 — request - #131 — response - #219 — debug ## Permissions and access ### Permissions - `storage` - `activeTab` - `tabs` - `contextMenus` - `declarativeNetRequest` ### Host permissions - `` ### Content script matches - `` ## Safety - **Risk impact:** High risk impact - **Risk likelihood:** High risk likelihood ### Analysis details - Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern. - This extension has low user count. Unpopular extensions may not be stable or safe. > Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing). ## Similar extensions and apps - [Mock Express](https://chrome-stats.com/d/mock-express) — 57 users - [ModResponse Mock replay API](https://chrome-stats.com/d/modresponse-mock-replay-api) — 33 users - [tweak: mock and modify HTTP requests](https://chrome-stats.com/d/tweak-extension) — 1,517 users, 4.14 / 5 - [Interceptor](https://chrome-stats.com/d/xhr-interceptor) — 129 users, 3.40 / 5 - [API Mock Generator](https://chrome-stats.com/d/api-mock-generator) — 1 users - [API Response Mocker](https://chrome-stats.com/d/api-response-mocker) - [Mocklet](https://chrome-stats.com/d/mocklet) — 4 users - [Requestman](https://chrome-stats.com/d/requestman) — 1 users - [Parrot API mocking Pro](https://chrome-stats.com/d/parrot-api-mocking-pro) — 2 users - [APIlot](https://chrome-stats.com/d/apilot) - [API MOCK](https://chrome-stats.com/d/api-mock) - [Apifox Browser Extension](https://chrome-stats.com/d/apifox-browser-extension) — 23 users --- Source: [Chrome-Stats](https://chrome-stats.com/d/moq-mock-api-requests)