ApiTester — API Request Tester & Fuzz Testing

Capture, replay and fuzz test API requests. AI-powered security analysis. Edit payloads, find bugs in your browser.

ApiTester is a developer tool that helps you capture, inspect, replay, and test API requests directly in your browser. Instead of switching to external tools, you can monitor and debug network requests from the page you are currently using. ApiTester runs in the side panel and works with live traffic from the active tab. Network monitoring only starts when the user explicitly enables it for the current tab. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ KEY FEATURES CAPTURE Monitor XHR, Fetch, and GraphQL requests from the active tab. Easily filter requests by method, status code, or URL. INSPECT View request and response details including headers, query parameters, and JSON bodies in a readable format. REPLAY Modify API requests and send them again to test different scenarios and behaviors. FUZZ TESTING Generate different payload variations automatically and test how APIs respond to unexpected or edge-case inputs. AI-ASSISTED ANALYSIS (OPTIONAL) ApiTester can analyze captured requests and suggest testing ideas such as payload variations or logic edge cases. This feature is optional and only runs when enabled by the user. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ WHO IT IS FOR • Developers testing REST or GraphQL APIs • QA engineers validating API behavior • Security testers exploring edge cases and logic issues • Anyone who wants to debug and inspect network requests in the browser ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ HOW IT WORKS 1. Open the ApiTester side panel. 2. Enable monitoring for the current tab. 3. Use the website normally and observe requests. 4. Inspect, modify, and replay API calls. 5. Run fuzz tests or optional AI-assisted analysis. All request processing happens locally in your browser. Data is only sent to external AI services if the user enables AI analysis. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ IMPORTANT ApiTester is intended for debugging and testing APIs. Only use it on applications and APIs that you are authorized to test.