Yes, successfully logging in with a passkey will update the user's last login instant.

However, there are edge cases where a passkey can be used without updating the last login timestamp:

Scenarios where passkey use doesn't update last login:

Login flow interrupted — The user authenticates with the passkey, but the login is stopped before completion due to:

Failed MFA challenge User action requirement (e.g., forced password reset) Account lock or suspension Login validation Lambda or transactional webhook rejecting the login

WebAuthn assertion without login — If the user performed a WebAuthn assertion directly via the API, this counts as using the passkey but does not constitute a full login flow and therefore doesn't update the last login instant. The Complete a WebAuthn Passkey Assertion API validates the WebAuthn ceremony but "does not authenticate the user into an application." This is different from the Complete a WebAuthn Passkey Authentication API, which validates the passkey and authenticates the user, thus updating the last login instant.

Summary

A passkey being "used" is not the same as a completed login. The last login timestamp only updates when the authentication flow completes successfully and issues a token.

Related Documentation Complete a WebAuthn Passkey Authentication - The API that validates passkeys and authenticates users (updates last login) Complete a WebAuthn Passkey Assertion - The API that only validates passkeys without authenticating (does not update last login) Authentication With WebAuthn & Passkeys - Complete guide to WebAuthn/passkey authentication in FusionAuth Update Login Instant API - Manual API for updating login instants when implementing custom SSO Setting Up User Account Lockout - How account lockouts can interrupt login flows

Hi James,

Glad to help! Let us know if you have any more questions.

If you're using PostgreSQL the size is essentially unlimited. With MySQL it is 16 MB.

There are few exceptions to this rule where we may be using a 64 KB column if you're on MySQL.

I wouldn't recommend storing that much data however. If you're using Elasticsearch, the custom data on the User will be indexed, and Elasticsearch will eventually hit a limit as well.

@le-nnyburkdoll

This guide might be helpful to you: https://fusionauth.io/docs/v1/tech/guides/user-search-with-elasticsearch

Thanks,
Dan

If you use the advanced registration forms, you can edit user data now. This was recently released as a premium feature (requiring a paid license; more info here).

More info on setting up the user data editing screen: https://fusionauth.io/docs/v1/tech/guides/advanced-registration-forms/#editing-user-data-in-the-admin-ui