How to Implement Phone Number Authentication in FlutterFlow with OTP

Written by: Manish Methani

January 14, 2025 at 6:21pm IST. 2 min 15 sec read

Secure Login Made Simple

Phone number authentication in FlutterFlow with OTP is a game-changer for app security and user experience. It adds an extra layer of trust to your app while making login seamless for your users. 💡

In this tutorial, I’ll guide you step-by-step on how to:

• Set up Phone Authentication in FlutterFlow.
• Implement OTP verification.
• Test your app on a physical device for real-world validation.

By the end of this tutorial, you’ll have the skills to build a professional-grade authentication system without writing a single line of code.

Tutorial Highlights

In this video, I’ll cover:

1. Firebase Setup: Connecting your FlutterFlow project to Firebase for authentication.
2. Phone Auth Basics: Configuring your app to send OTPs for phone number authentication in FlutterFlow.
3. Customizing Login Flows: Adding your branding to the login experience.
4. Real Device Testing: Ensuring everything works perfectly on a physical device.

📽️ Watch the full tutorial here:

Summary

Here’s a quick recap of the steps we followed:

1. Link Firebase to your FlutterFlow project.
2. Enable phone number authentication in FlutterFlow via the Firebase Console.
3. Add a custom login screen in FlutterFlow with phone number input and OTP.
4. Configure OTP verification logic in FlutterFlow using actions.
5. Test the login flow on a physical device for real-world usability.

Extra Tips

• Brand Your Login Screen: Use FlutterFlow’s customization tools to create a seamless and professional experience.
• Testing on Multiple Devices: Always test your app on different devices to ensure compatibility.

Wrap Up

By following this tutorial, you’ve taken a significant step toward building secure and user-friendly apps with FlutterFlow.