Culprit

Capture API failures, find reliable test selectors, and create actionable bug reports in one free, privacy-first Chrome extension.

Every failure leaves a clue. Capture API failures, find reliable test selectors, and create actionable bug reports, all in one free, privacy-first Chrome extension. It is free to use; it is proprietary software and its source code is private. A page breaks and the bug report says "it doesn't work". Culprit shows what really happened: you did this → this broke → copy it. Switch it on for a site and it watches that site's API calls (fetch and XHR), console errors, uncaught errors and broken resources, then ties each problem to the click that set it off. For example: "Clicked Submit order → POST /api/orders returned 500 two tenths of a second later". What you get • The exact failing call: full URL, status, timing, headers, and the request and response bodies • What the server said, the trace id to hand to a developer, and a short "What to check" list that fits the problem • One recommended selector for the element you clicked, written for the test framework you choose. It says whether the selector finds exactly one element and how likely it is to keep working; one that matches several elements is never called "Recommended". "Check these on the page now" re-counts them on the live page • A copy-ready bug report in one press: steps to reproduce, the exact request, the server's answer and the recommended selector. Also ticket text, a ready-to-run test and a JSON export • An Activity list with All, Failures and Clicks tabs, repeated problems grouped, and a Details screen for each with a clearly labelled "Possible cause" • Only what matters: problems from the page itself or caused by you; tracker noise is hidden, with one switch to show it • Works inside the iframes of the site you enabled (embedded checkouts and widgets) • Inspect mode: hover an element to see its selector live in the side panel. Nothing is drawn on the page • A Screenshot button shows an image of the page in the side panel, ready to copy into a ticket • Shortcuts: Alt+Shift+C copies the bug report for the latest problem; Alt+Shift+S takes a screenshot What Culprit records (and where it stays) Before you switch a site on, a notice in the popup and side panel says what is captured, and nothing is recorded until you press "Enable recording". It records clicks, failed API requests and responses, and console errors: the web addresses (URLs) of pages and calls, status, headers and bodies, and the label and selector of each element you click. It needs that to match each problem with its cause. Screenshots are taken only when you ask. Captured data stays on your device and is never transmitted by Culprit. Because it records what the site sends, that content can include personal or sensitive data; masking is best effort, so review anything you copy or export before you share it. See the privacy policy for the limits. Private by design • Free. No account, no servers, no analytics, no ads • Nothing leaves your browser. The extension makes no network requests of its own • Runs only on sites you turn on, one site at a time (subdomains included); Chrome asks you first. Desktop notifications are optional and ask for their own permission only if you switch them on • Sensitive values are masked before anything is stored: credential headers, password, token and secret fields, key=value pairs in JSON, forms, URLs and text, signed-URL signatures, card numbers, plus your own extra field names. Masking is applied in the page and again in the extension's background process. Names, email addresses and other personal information are not masked, and an unusual secret can remain • "Disable" on a site stops recording and deletes what was recorded there • Data is kept in session storage and dropped when the tab or browser closes Made for QA and developers • Works with single-page apps • Ignores requests cancelled by navigation, to cut noise • Optional setting to hide status-0 errors (usually ad blockers or offline) • Dark theme by default, light and system themes available How to use it 1. Open the site you want to debug and click the Culprit icon. 2. Read the notice, press "Enable recording" and accept Chrome's permission prompt. 3. Use the page. The popup shows what broke; "Open in side panel" shows everything. 4. Press "Copy bug report" and paste it into your tracker. Feedback is welcome: use the Support section of this page or write to business.movecurious@gmail.com. Culprit's use of user data complies with the Chrome Web Store User Data Policy, including the Limited Use requirements.