How do I change the colors and styling in FirebaseUI?

FirebaseUI uses CSS variables for theming: override variables like --fui-primary and --fui-background in your CSS, or use the Tailwind-specific import for utility-based styling, as explained in the Styling section.

FirebaseUI vs Supabase Auth UI: which should I use?

FirebaseUI is optimized for Firebase authentication with deep integration and pre-built components. Supabase Auth UI is tailored for Supabase and might offer different features. Choose based on your backend: FirebaseUI for Firebase, Supabase Auth UI for Supabase.

Does FirebaseUI work with Vue.js or Svelte?

No, FirebaseUI only officially supports React, Angular, and Shadcn. For Vue.js or Svelte, you'd need to use the framework-agnostic core package to build custom UI, which requires more effort.

How to implement phone authentication with FirebaseUI?

Use the PhoneAuthForm or PhoneAuthScreen components, configure the recaptchaVerification behavior for reCAPTCHA settings, and handle verification flows via the provided hooks or methods in the reference API.

Is FirebaseUI v7 ready for production use?

Version 7 is in beta, so it may have unresolved bugs or breaking changes. Check the migration guide and release notes carefully before deploying to production, and consider testing thoroughly in staging.

How to add a custom OAuth provider not listed in FirebaseUI?

FirebaseUI only supports standard Firebase OAuth providers (e.g., Google, GitHub). For custom providers, you might need to extend the core logic or build a custom UI using the framework-agnostic package and Firebase SDK directly.

What's the performance impact of using FirebaseUI?

FirebaseUI adds bundle size from its components and dependencies, but it's optimized for modern frameworks. For lightweight projects, consider if the convenience outweighs the overhead, especially with multiple behaviors enabled.

Firebase UI — Firebase Auth UI Components

What is Firebase UI?

FirebaseUI is an open-source JavaScript library that provides ready-to-use, customizable UI components for Firebase authentication. It simplifies adding secure sign-in flows—including email/password, OAuth, phone auth, and multi-factor authentication—to web applications built with React, Angular, or Shadcn, reducing boilerplate code and enforcing best practices.

Target Audience

Web developers using Firebase for authentication who want to quickly implement production-ready sign-in interfaces without building UI from scratch, particularly those working with React, Angular, or Shadcn-based projects.

Value Proposition

It saves significant development time by offering pre-built, accessible, and themable components that handle complex Firebase auth flows, while providing flexibility through behaviors and a framework-agnostic core for custom implementations.

FirebaseUI is an open-source JavaScript library for Web that provides simple, customizable UI bindings on top of Firebase SDKs to eliminate boilerplate code and promote best practices.

Use Cases

Best For

Adding Firebase authentication to a React or Angular application quickly
Implementing multi-factor authentication (MFA) with TOTP or SMS
Building a custom authentication UI with Firebase backend logic
Creating themed sign-in flows that match your app's design system
Supporting multiple OAuth providers (Google, Apple, GitHub, etc.)
Handling complex auth scenarios like anonymous user upgrades

Not Ideal For

Projects using authentication backends other than Firebase (e.g., Supabase, Auth0, or custom solutions)
Applications built with frameworks not officially supported (e.g., Vue.js, Svelte, or vanilla JavaScript)
Teams requiring immediate, out-of-the-box multi-language support beyond English
Developers who need to avoid beta software due to stability concerns or production deadlines

Pros & Cons

Pros

Comprehensive Auth Coverage

Supports all major Firebase authentication methods including email/password, OAuth, phone auth, MFA, and anonymous login, with dedicated components for each flow as listed in the reference API.

Multi-Framework Integration

Offers first-party packages for React, Angular, and Shadcn UI, with a framework-agnostic core (@firebase-oss/ui-core) for custom implementations, reducing framework lock-in.

Customizable Behaviors

Provides configurable logic via behaviors like auto anonymous login, anonymous user upgrades, and reCAPTCHA settings, allowing fine-tuned control over auth scenarios without boilerplate code.

Built-in Best Practices

Enforces secure Firebase authentication patterns out of the box, such as proper handling of MFA enrollments and OAuth redirects, as detailed in the behaviors section.

Cons

Beta Status and Migration Pain

Version 7 is a complete rewrite currently in beta, requiring a dedicated migration guide from v6 and potentially introducing breaking changes or instability for early adopters.

Limited Built-in Localization

Only provides English (en-US) translations by default, forcing developers to manually register locales for other languages using the registerLocale function, which adds overhead for international apps.

Complex Framework-Specific Setup

Integration steps vary significantly per framework (e.g., Shadcn requires registry edits, Angular needs AngularFire), making setup more involved than a drop-in solution.

Frequently Asked Questions

What is Firebase UI?

Target Audience

Value Proposition

Use Cases

Best For

Adding Firebase authentication to a React or Angular application quickly
Implementing multi-factor authentication (MFA) with TOTP or SMS
Building a custom authentication UI with Firebase backend logic
Creating themed sign-in flows that match your app's design system
Supporting multiple OAuth providers (Google, Apple, GitHub, etc.)
Handling complex auth scenarios like anonymous user upgrades

Not Ideal For

Projects using authentication backends other than Firebase (e.g., Supabase, Auth0, or custom solutions)
Applications built with frameworks not officially supported (e.g., Vue.js, Svelte, or vanilla JavaScript)
Teams requiring immediate, out-of-the-box multi-language support beyond English
Developers who need to avoid beta software due to stability concerns or production deadlines

Pros & Cons

Pros

Comprehensive Auth Coverage

Supports all major Firebase authentication methods including email/password, OAuth, phone auth, MFA, and anonymous login, with dedicated components for each flow as listed in the reference API.

Multi-Framework Integration

Offers first-party packages for React, Angular, and Shadcn UI, with a framework-agnostic core (@firebase-oss/ui-core) for custom implementations, reducing framework lock-in.

Customizable Behaviors

Provides configurable logic via behaviors like auto anonymous login, anonymous user upgrades, and reCAPTCHA settings, allowing fine-tuned control over auth scenarios without boilerplate code.

Built-in Best Practices

Enforces secure Firebase authentication patterns out of the box, such as proper handling of MFA enrollments and OAuth redirects, as detailed in the behaviors section.

Cons

Beta Status and Migration Pain

Version 7 is a complete rewrite currently in beta, requiring a dedicated migration guide from v6 and potentially introducing breaking changes or instability for early adopters.

Limited Built-in Localization

Complex Framework-Specific Setup

Integration steps vary significantly per framework (e.g., Shadcn requires registry edits, Angular needs AngularFire), making setup more involved than a drop-in solution.

Frequently Asked Questions

Firebase UI

What is Firebase UI?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

Firebase UI

What is Firebase UI?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?