API Tester Pro - REST API Client & HTTP Request Maker

Free Postman alternative. Test REST APIs, send HTTP requests, debug endpoints and import collections.

🚀 API TESTER PRO — THE FASTEST API TESTING TOOL FOR YOUR BROWSER Stop switching between your browser and Postman. API Tester Pro is a free, lightweight, blazing-fast REST API client that runs directly inside Chrome. Built by developers, for developers. ⚡ WHY 50,000+ DEVELOPERS ARE SWITCHING FROM POSTMAN: ✅ Instant startup — no app to download, no sign-up required ✅ Zero latency — runs natively in your browser ✅ Works offline — test APIs without internet ✅ Import Postman collections in one click ✅ 100% free — no paid tiers, no feature gates ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🛠️ COMPLETE FEATURE LIST: ▸ API REQUEST BUILDER Send GET, POST, PUT, PATCH, DELETE, OPTIONS, and HEAD requests. Full support for query parameters, custom headers, JSON body, form data, x-www-form-urlencoded, and raw text. Upload files with multipart form data. ▸ BEAUTIFUL RESPONSE VIEWER Pretty-printed JSON with syntax highlighting. Collapsible tree view for nested objects. View response headers, status codes, response time, and payload size. Copy or download responses instantly. ▸ COLLECTIONS & FOLDERS Organize your API requests into collections with nested folders. Save, rename, duplicate, and drag-and-drop to reorder. Just like Postman — but faster. ▸ ENVIRONMENT VARIABLES Create multiple environments (Development, Staging, Production). Use {{variable}} syntax in URLs, headers, body, and auth fields. Switch environments with one click. Global variables supported. ▸ AUTHENTICATION Bearer Token, Basic Auth, API Key (header or query), and OAuth 2.0 with Client Credentials flow. Auto-attach tokens to requests. ▸ REQUEST HISTORY Every request is automatically saved. Search, filter by method, and re-run any previous request instantly. Grouped by date for easy browsing. ▸ TABS Work on multiple requests simultaneously with browser-style tabs. Unsaved changes indicator. Close, duplicate, and reorder tabs. ▸ CODE GENERATOR Generate ready-to-use code snippets in: • JavaScript (fetch) • cURL • Python (requests) • Node.js (http) • PHP (cURL) One-click copy to clipboard. ▸ IMPORT & EXPORT Import Postman v2.0 and v2.1 collections. Export your collections. Full backup and restore. Migrate from Postman in seconds. ▸ PRE-REQUEST SCRIPTS Write JavaScript that runs before each request. Set variables dynamically, add timestamps, generate tokens. Postman-compatible pm.* API. ▸ TEST SCRIPTS & ASSERTIONS Validate API responses with test scripts. Assert status codes, response times, JSON values, headers. See pass/fail results instantly. Compatible with pm.test() and pm.expect() syntax. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔥 ADVANCED FEATURES (BEYOND POSTMAN): ▸ NETWORK CAPTURE (EXCLUSIVE) Capture live API calls from any website tab. See every XHR and fetch request the page makes. Import captured requests into your workspace with one click. No other extension does this. ▸ RESPONSE COMPARISON Compare two API responses side-by-side. Highlight added, removed, and changed fields. JSON structural diff and line-by-line diff. Perfect for regression testing. ▸ MOCK SERVER Create mock API endpoints that return predefined responses. Simulate backend APIs before they're built. Perfect for frontend development and testing. ▸ PERFORMANCE ANALYTICS Track response times across all your endpoints. See trends, averages, P95 latency, and success rates. Identify slow APIs instantly. ▸ REQUEST SCHEDULER Schedule API requests to run automatically at intervals. Health checks, data sync, monitoring — all automated. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🎨 DESIGNED FOR DEVELOPERS: • Dark mode by default (easy on the eyes) • VS Code-inspired interface • Resizable split panels • Keyboard shortcuts (Ctrl+Enter to send, Ctrl+T new tab, Ctrl+S save) • Right-click context menus everywhere • Instant loading (<1 second startup) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔒 PRIVACY & SECURITY: • All data stored locally on your device • No accounts required • No data sent to any server • No analytics or tracking • Open architecture — your data stays yours ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 📋 PERFECT FOR: • Frontend developers testing backend APIs • Backend developers debugging endpoints • QA engineers running API tests • DevOps engineers monitoring services • Students learning about REST APIs • Anyone migrating away from Postman ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔄 MIGRATING FROM POSTMAN? 1. Export your Postman collection as JSON 2. Click Import in API Tester Pro 3. All your requests, folders, and structure are preserved 4. Start testing immediately ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 💬 FREQUENTLY ASKED QUESTIONS: Q: Is this really free? A: Yes, 100% free. No premium tiers, no feature restrictions. Q: Does it work offline? A: Yes. All data is stored locally using IndexedDB. You can build and save requests offline. Q: Can I import my Postman collections? A: Yes. We support Postman v2.0 and v2.1 collection formats. Q: Is my data secure? A: All data stays on your device. Nothing is sent to any external server. Q: Does it support GraphQL? A: GraphQL support is coming in the next update. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⭐ Love API Tester Pro? Leave a 5-star review! Your rating helps other developers discover this tool. 🐛 Found a bug? Have a feature request? Email us: mohitmishra001.mm@gmail.com