Auth0 vs Firebase Authentication: Full Comparison (2026)
Pricing, features, scores, and a clear verdict on which one is right for you.
The bottom line
Auth0 Essentials starts at $35/month for 500 MAUs. Firebase Authentication is free for 50,000 MAUs on email/password and social providers. At 5,000 MAUs, Auth0 costs $35+/month; Firebase is $0. The free-tier gap is enormous — Firebase's 50K MAU free tier covers most consumer apps indefinitely. The enterprise feature gap is where Auth0 justifies its cost. Auth0 offers production-ready SAML 2.0, SCIM provisioning, AD/LDAP federation, fine-grained authorization, HIPAA BAA, and FedRAMP ATO certifications. Firebase Auth's enterprise tier (Identity Platform) adds some of these but with more complexity and mixed developer reviews on SAML implementation. For B2B SaaS where enterprise customers require SSO as a day-one procurement requirement, Auth0 is the safer choice — enterprise IT departments trust Okta's compliance credentials in a way Firebase's Google Cloud governance hasn't fully established. Firebase's strength is mobile: the Flutter/Firebase auth combination and native Android/iOS SDKs are among the most polished auth implementations available. Social provider integration (Google, Apple) is trivially easy — one line of code for each. Firebase's phone SMS auth is the hidden cost: $0.0075/SMS in the US, scaling to $0.34/SMS internationally. High-SMS-volume consumer apps (fintech OTP, gig economy verification) face real cost exposure. Auth0's SMS costs are similarly priced but its predictable per-MAU model is easier to budget. Decision: consumer apps under 50K MAU or Firebase ecosystem → Firebase Auth. B2B SaaS with enterprise SSO requirements or compliance certifications → Auth0.
At a glance
| Auth0 | Firebase Authentication | |
|---|---|---|
| Our score | 79/100 | 76/100 |
| Starting price | Free | Free |
| Free tier | Yes | Yes |
| Best for | Enterprise authentication and identity platform | Google-backed auth with generous free tier for mobile and web |
Pricing comparison
Firebase Authentication
Pricing verified 2026-04-16
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Feature comparison
core
| Feature | Auth0 | Firebase Authentication |
|---|---|---|
| OAuth 2.0 / OIDC | Yes | No |
| Social login | Yes | No |
| MFA | Yes | No |
| Custom domains | Essentials+ | No |
| Passwordless | Yes | No |
| Email/password | No | Yes |
| Google OAuth | No | Yes |
| Apple OAuth | No | Yes |
| Phone SMS | No | Yes |
| Anonymous auth | No | Yes |
advanced
| Feature | Auth0 | Firebase Authentication |
|---|---|---|
| SAML 2.0 | Professional+ | No |
| LDAP/AD | Professional+ | No |
| SCIM provisioning | Enterprise | No |
| Fine-grained auth | Enterprise | No |
| HIPAA BAA | Enterprise | No |
| Multi-tenancy | No | Blaze |
| SAML SSO | No | Blaze ($0.015/MAU) |
| Custom claims | No | Yes |
| App Check | No | Yes |
| Blocking functions | No | Yes |
integrations
| Feature | Auth0 | Firebase Authentication |
|---|---|---|
| Next.js | Yes | No |
| React | Yes | No |
| Salesforce | Yes | No |
| Okta Workflows | Yes | No |
| Zapier | Yes | No |
| Firebase (all products) | No | Yes |
| Google Cloud | No | Yes |
| Flutter | No | Yes |
| Android/iOS SDKs | No | Yes |
| Web SDK | No | Yes |
Ratings breakdown
What the data tells us
Key capabilities you'd miss
Choosing Auth0 means going without Email/password, Google OAuth, Apple OAuth (which Firebase Authentication offers). Choosing Firebase Authentication means losing OAuth 2.0 / OIDC, Social login, MFA. These are the features that typically drive the final decision — check whether your workflow depends on any of them before committing.
What company size tells you
Firebase Authentication (100,000+ employees) has the engineering bench to ship features across many fronts but may iterate slower on individual requests. Auth0 (1,000+ employees) typically ships faster on its core product but may lag on peripheral features. Consider which matters more for your roadmap.
Choose Auth0 if...
- You want a free tier to get started
- You value powerful features over simplicity
- You need enterprise-grade capabilities
Choose Firebase Authentication if...
- You want a free tier to get started
- You value an intuitive, easy-to-use interface
- Getting strong value for money is a priority
Frequently asked questions
Is Auth0 or Firebase Authentication better?
Auth0 scores 79/100 compared to Firebase Authentication's 76/100 on VendorVS. However, the best choice depends on your needs — Auth0 excels at ease of use (7/10) while Firebase Authentication scores 8/10.
How much does Auth0 cost compared to Firebase Authentication?
Auth0 starts at free (free tier available). Firebase Authentication starts at free (free tier available). Auth0 is the more affordable option.
Does Auth0 or Firebase Authentication have a free plan?
Yes, both Auth0 and Firebase Authentication offer free tiers, so you can try each before committing to a paid plan.
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