Firebase Auth vs Auth0

Side-by-side — pricing, strengths, tradeoffs, and fit.

Firebase Auth

Drop-in authentication from Google Firebase with generous free tier and easy social login.

Auth0

Enterprise-grade authentication and authorization platform with extensive identity-provider support.

Firebase Auth

Auth0

At a glance

Free TierEnterprise

● Established·From $0 (pay for phone auth/Identity Platform)

Free TierEnterprise

● Established·From $35/mo

Overview

One-liner

Drop-in authentication from Google Firebase with generous free tier and easy social login.

One-liner

Enterprise-grade authentication and authorization platform with extensive identity-provider support.

Maturity

Established

Maturity

Established

Open source

✕ No

Open source

✕ No

Pricing

Free tier

✓ Available

Unlimited email/social auth; phone auth metered

Free tier

✓ Available

25,000 monthly active users on the free plan

Starts at

$0 (pay for phone auth/Identity Platform)

Starts at

$35/mo

Model

Usage-based

Model

Per MAU

Enterprise

✓ Available

Enterprise

✓ Available

Best for

✓ Best for

Mobile and web apps already on FirebaseNative integration with Firestore and GCP

Side projects needing free authFree email/social at any scale

✓ Best for

Enterprise B2B apps needing SSO/SAMLMature enterprise connections and compliance

Teams needing fine-grained authorizationRBAC and Actions cover complex authz

Not ideal for

✕ Not for

—

✕ Not for

—

Strengths

↑ Strengths

Generous free tier

Tight Firebase/GCP integration

Fast to integrate

↑ Strengths

Deep enterprise identity features

Huge ecosystem of connections/rules

Battle-tested at scale

Weaknesses

↓ Weaknesses

Lock-in to Firebase/Google

Limited enterprise SSO without Identity Platform

↓ Weaknesses

Essential enterprise features like Enterprise Connections and SCIM are not available on the Essentials or Professional plans.

The free tier requires credit card verification to enable custom domains.

Full Firebase Auth profile →Full Auth0 profile →