API Tester — REST, WebSocket & GraphQL Client

Test any API without CORS errors. REST client, WebSocket tester & GraphQL-collections, code snippets. By BrowserDock.

Test any API directly from your browser — with NO CORS errors. Unlike web-based API tools, this extension can send requests to any endpoint, including localhost and APIs without CORS headers. ⚡ WHY THIS EXTENSION? Web-based API testers are blocked by browser CORS rules. This extension uses host permissions to send requests to ANY API — localhost, staging servers, third-party APIs — no proxy, no workarounds. 🛠 FEATURES ✓ Full REST client — GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS ✓ No CORS restrictions — test localhost and any API ✓ Two layouts — quick tests in the browser side panel, or full-screen mode for serious work ✓ WebSocket tester — connect, send, and receive messages in real time ✓ GraphQL mode — query and variables editors with endpoint auto-detection ✓ Body formats — JSON, URL-encoded, Form Data, Raw, GraphQL ✓ Authentication — Bearer token and Basic auth ✓ Environment variables — use {{base_url}} style placeholders across requests ✓ Collections — save, organize, import and export requests as JSON ✓ Code snippets — generate cURL, JavaScript, Python, and PHP code ✓ Response inspector — syntax-highlighted JSON, headers, cookies, timing breakdown ✓ Response diff — compare two responses side by side ✓ Request history — quickly re-run recent requests 🔒 PRIVACY FIRST Everything runs entirely on your device. Requests go directly from your browser to the target API — nothing is proxied, logged, or collected. History, collections, and environments are stored only in your browser's local storage. No account. No sign-up. No tracking. Part of the BrowserDock developer tools family — https://browserdock.dev