Details about the API including example usage code snippets and its motivation, privacy, and security considerations are described in EXPLAINER.md. Support for WebHID in extension service workers is described in WEBHID_IN_EXTENSION_SERVICE_WORKERS_EXPLAINER.md.
This API is implemented in Blink. It is available in browsers based on Chromium 89 and later, such as Google Chrome and Microsoft Edge. Individual Chromium-based browsers may choose to enable or disable this API. Chromium-based Android browsers do not support this API because Android itself does not provide a direct API for accessing HID devices (Chromium issue 964441). For the same reason this API is not available in Android WebView (Chromium issue 1164125).