Firebase Auth

Firebase Authentication pricing follows Google Cloud Identity Platform. Tier 1 providers such as email, phone, anonymous, and social sign-in are free for the first 50,000 monthly active users, then billed per MAU on a published tiered schedule. Tier 2 providers such as OIDC and SAML are free for the first 50 MAUs, then billed separately. Phone and MFA authentication are charged per message sent.

• Identity Platform counts monthly active users by authentication method, and inactive stored users do not incur MAU charges.
• Anonymous users can be excluded from the MAU count if automatic cleanup is enabled.
• Phone Number Verification and MFA should be modeled separately because each message sent is billable.
• Auth should be reviewed alongside the rest of the Firebase bill, because sign-in growth often correlates with Firestore and Functions growth.

Pricing may change - verify on the official site. View official pricing