How to use developer tools to check and debug a web manifest and Service Worker?

Progressive web applications actively use Service Worker and Web App Manifest technologies to work offline and install on a device. Developer tools provide a special Application section for deep analysis and testing of these components, guaranteeing their correct functioning in a production environment.

To check the manifest, open the Application tab and select Manifest in the left sidebar menu. This displays all metadata about your application, including the name, icons of various sizes, theme colors, and the start URL. The browser automatically audits the manifest and outputs warnings if required fields are missing or icon files are not found at the specified path.

The Service Workers section on the same panel allows you to manage the lifecycle of background scripts. You can see the current status of the registered script, its scope, and source. Convenient checkboxes are available to simulate offline operation, force-update the script on every page reload, or completely unregister the Service Worker.

Special event emulation buttons are provided directly from the panel interface for testing push notifications and background synchronization. This saves the developer from having to write additional code to trigger these system events and allows for quickly finding bugs in the caching logic of static and dynamic resources.