v131 · miscellaneous

Web Authentication API: PublicKeyCredential’s getClientCapabilities() method

getClientCapabilities() method allows to determine which WebAuthn features are supported by the user's client. The method returns a list of supported capabilities, allowing developers to tailor authentication experiences and workflows based on the client's specific functionality.

concepts

  1. WebAuthn getClientCapabilities

    Single call returning supported WebAuthn features.

  2. Gate conditional UI

    Use one capability call to decide whether to render passkey-autofill or a fallback button — the canonical sign-in form case.

  3. Capability explorer

    Tile per capability. Probe your browser and see which extensions and signals it supports.

  4. Sign-in surface picker

    Toggle capability checkboxes to simulate browsers. The decision tree picks autofill vs CTA vs QR vs fallback — and renders the mock surface.

why it shipped

Different clients and authenticators offer varying levels of support for WebAuthn features. This disparity can lead to a fragmented user experience, where some users might encounter errors or be unable to utilize certain authentication options. Providing a way for developers to determine client capabilities enables them to create more robust authentication flows that adapt to these variations.

references