MockMaster

Mock API responses instantly. Intercept HTTP requests and return custom responses for testing and development.

Mock Master - The only API Mocker you'll need Mock API responses instantly with the most intuitive and powerful API mocking extension for Chrome. Perfect for frontend development, testing, and demos. ⭐ KEY FEATURES • Beautiful Modern UI - Stunning React-based interface that's a pleasure to use • Instant API Mocking - Intercept and mock any HTTP request (GET, POST, PUT, DELETE, PATCH) • Flexible URL Matching - Support for full URLs, pathnames, and powerful regex patterns • Custom Responses - Set any status code (200, 404, 500, etc.) and response body • JSON & Text Support - Full support for JSON responses and plain text • One-Click Toggle - Enable or disable rules instantly without deleting them • Visual Indicators - Color-coded HTTP methods and status codes for easy identification • Local Storage - All your mock rules are stored securely in your browser only • Zero Configuration - Install and start mocking immediately, no setup required 🎯 PERFECT FOR Frontend Developers • Build features without waiting for backend APIs • Test UI components with perfect mock data QA Engineers • Reproduce specific error scenarios • Test edge cases and error handling • Validate UI behaviour with different response codes Product Managers • Create demos with controlled, consistent data • Show features before backend is ready • Present different user scenarios DevOps & Backend Developers • Simulate production issues in safe environments • Test frontend integration without affecting real APIs • Debug API-related issues locally 💡 HOW IT WORKS 1. Click the extension icon to open the beautiful popup 2. Click "Add Rule" to create a new mock 3. Enter your URL pattern (e.g., /api/users or https://api.example.com/.*) 4. Select HTTP method (GET, POST, PUT, DELETE, PATCH) 5. Set response status code (200, 404, 500, etc.) 6. Add your response body (JSON or plain text) 7. Toggle the rule on/off as needed 8. Browse any website - matching requests are automatically mocked! 📝 URL PATTERN EXAMPLES Full URL: https://api.example.com/users Pathname: /api/users Regex Pattern: /api/users/.* Simple Pattern: example.com 🔒 PRIVACY FIRST Your privacy matters. Mock Master: • Stores ALL data locally in your browser only • Never collects or transmits any personal information • Never tracks your browsing activity • Never shares data with third parties • No analytics, no telemetry, no cookies All mock rules stay on your device. Always. 🚀 WHY CHOOSE MOCK MASTER? Unlike other API mocking tools: ✓ Stunning UI - Not just functional, but beautiful ✓ Instant Setup - No configuration files or complex setup ✓ Powerful Regex - Advanced pattern matching for complex scenarios ✓ Visual Feedback - See at a glance which rules are active ✓ Developer-Friendly - Built by developers, for developers 🆚 BETTER THAN ALTERNATIVES • More intuitive than Requestly • More powerful than Mokku • Better UI than all competitors • Completely free and focused on user experience 📊 USE CASES ✓ Mock third-party APIs during development ✓ Test error handling with different status codes ✓ Simulate slow API responses with delay ✓ Create offline development environments ✓ Build demos with perfect, consistent data ✓ Reproduce production bugs locally ✓ Test authentication flows without real credentials ✓ Validate UI with various response payloads --- ⚡ Install Mock Master today and transform your development workflow! Perfect for teams and individual developers who value beautiful tools that just work.