Introduction

Phone number login is now one of the fastest-growing authentication methods in mobile apps. Users prefer OTP-based login because it is quick, passwordless, and secure.

With the new Phone Verification (Preview) feature inside Firebase, Android developers can enable one-tap phone number retrieval directly from the device SIM.

If you are building Android apps and want:

• Faster onboarding
• Higher signup conversion
• Lower login friction
• Reduced password resets

Then this guide explains everything you need to know.