> ## Documentation Index
> Fetch the complete documentation index at: https://docs.corbado.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Passkey Login: One-Tap

> This flow explains the journey of a user logging in via One-Tap passkey button.

## One-Tap Login Flow

Users logging in via desktop and mobile browsers follow a standard login flow enriched by the One-Tap passkey experience, leading to higher login rates on trusted devices.

<Info>
  **Feature Documentation**: For comprehensive details about One-Tap Login implementation, benefits, and configuration, see the [Corbado Connect One-Tap Login feature documentation](/corbado-connect/features/one-tap-login).
</Info>

### Platform-Specific Implementations

The One-Tap Login experience adapts seamlessly to each platform's native authentication UI, ensuring users receive a familiar and trusted interface:

<Tabs>
  <Tab title="macOS" />

  <Tab title="Windows" />

  <Tab title="iOS" />

  <Tab title="Android" />
</Tabs>

<Steps>
  <Step title="Users log in via One-Tap">
    * Corbado detects the user has a passkey linked to the platform. User taps "Login with Passkey" button on the login screen to start authentication.
    * The button displays personalized information (e.g., "Login as [alice@example.com](mailto:alice@example.com)") for improved user recognition.
  </Step>

  <Step title="Automatic OS-native biometric modal appears">
    * The system prompts for available saved passkey using the browser's or OS-native modal (for example, Touch ID).
    * User verifies their identity using their screen lock (e.g., fingerprint, PIN, or face recognition).
    * The authentication happens locally on the device - no passwords are transmitted over the network.
  </Step>

  <Step title="Access granted">
    * User is seamlessly logged in and redirected to the dashboard.
    * The entire process typically completes in under 2 seconds.
  </Step>
</Steps>

## Technical Considerations

### Device Recognition

The One-Tap Login button appears intelligently based on:

* **Passkey availability**: Whether the user has previously created a passkey on this device
* **Browser support**: Automatic detection of WebAuthn compatibility
* **Session history**: Recognition of the last used account on the device

### Edge Cases and Fallbacks

<AccordionGroup>
  <Accordion title="Multiple accounts on the same device">
    When multiple accounts exist on a device, the One-Tap button defaults to the most recently used account. Users can easily switch accounts through a dropdown or "Use another account" option.
  </Accordion>

  <Accordion title="First-time device access">
    On a new device, users complete the standard authentication flow once. After successful passkey creation or migration, One-Tap Login becomes available for all subsequent visits.
  </Accordion>

  <Accordion title="Passkey unavailable scenarios">
    If a passkey becomes unavailable (e.g., deleted by user, browser issues), the system gracefully falls back to alternative authentication methods without user confusion.
  </Accordion>
</AccordionGroup>