AuthenticatorAssertionResponse: authenticatorData property

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The authenticatorData property of the AuthenticatorAssertionResponse interface returns an ArrayBuffer containing information from the authenticator such as the Relying Party ID Hash (rpIdHash), a signature counter, test of user presence, user verification flags, and any extensions processed by the authenticator.


An ArrayBuffer with a ArrayBuffer.byteLength of at least 37 bytes, which contains the data structure explained in Authenticator data.


See User login using the WebAuthn API for a detailed example.


Web Authentication: An API for accessing Public Key Credentials - Level 3
# dom-authenticatorassertionresponse-authenticatordata

Browser compatibility

BCD tables only load in the browser