Error Watcher is a Chrome extension designed for developers and testers that actively monitors web pages for JavaScript errors, console warnings, and network failures. This tool provides real-time notifications of issues, ensuring users can quickly address problems as they occur, even when the DevTools are not open. Key features include monitoring JavaScript exceptions, console errors, and failed network requests, with error counts displayed on the extension icon and detailed logs available in a popup.

The extension allows users to monitor all sites or limit the scope to specific domains and ports. It offers flexibility with pause and resume functionality, as well as independent capture controls for various error categories. Users can clear errors individually or all at once, and clicking on any error entry reveals detailed stack traces and source locations. Error Watcher is lightweight, ensuring user privacy with no external data storage or tracking.