Debug Buddy

Create API mocks and troubleshoot web apps: inspect network calls, simulate failures, replay sessions and reproduce API errors.

Debug Buddy is a developer tool to create API mocks and to analyze and troubleshoot web applications, whatever framework they use, right in Chrome, without adding anything to your project or changing your backend. When a screen breaks, loads slowly or shows the wrong data, Debug Buddy shows what happened between the browser and your APIs, and lets you reproduce the problem with mocks as many times as you need. Create mocks without a mock server: • Mock any API response: status, headers and body, even for endpoints that do not exist yet. • Simulate failures: HTTP errors (500, 404, 401…), slow responses, connection failures and responses that break the contract. • Adjust headers and bodies on the fly to test feature flags, tokens and edge cases. • Pause a call to examine it and edit status, headers and body before it continues. • Organize your mocks as reusable rules matched by URL, method, header or body. Analyze and troubleshoot: • Follow every network call of the tab in real time: method, URL, status, duration and size, with filters by method, status and text. • Inspect requests and responses: headers, body and timing. • Replay the session: the screen recording synced with a timeline of network calls, console errors and navigations. • Discover the page's stack: detection of 100+ technologies (frameworks, libraries, servers and analytics tools). • Get security recommendations (CSP, HSTS, cookies, CORS, mixed content) and performance recommendations (compression, caching, large payloads, unoptimized images). • Export and import sessions (.dbsession) to share a problem with your team. Privacy: your data stays in your browser (Chrome storage and IndexedDB). Debug Buddy does not send it to any Debug Buddy or third-party service. You choose what gets masked — headers, bodies, console output, form inputs — which domains are never recorded, and how long data is kept. While a tab is being analyzed, Chrome shows a "started debugging this browser" bar on it. This is expected: Debug Buddy uses Chrome's debugging API to see the page's network activity and apply your mocks.