Auth0 vs Firebase Auth / Identity Platform
Answer: As of 2026-10-31: Auth0 and Firebase Auth / Identity Platform tie at $0 for 1k users · no SSO; Auth0 wins 10k users · 1 SSO at $0/mo ($27/yr less than Firebase Auth / Identity Platform) [Firebase Auth / Identity Platform SSO assumes 200 SSO users per connection; at 2,000 per connection: Auth0 $0/mo, Firebase Auth / Identity Platform $29.25/mo].
Cost by MAU (no SSO)
| Monthly users | Auth0 | Firebase Auth / Identity Platform |
|---|---|---|
| 10k users | $0 Free | $0 Pay as you go |
| 50k users | $3,500 Essentials (B2C) | $0 Pay as you go |
| 100k users | — | $275 Pay as you go |
With enterprise SSO
| Scenario | Auth0 | Firebase Auth / Identity Platform |
|---|---|---|
| 1k users · no SSO | $0 Free | $0 Pay as you go |
| 10k users · 1 SSO | $0 Free | $2.25 Pay as you go |
| 50k users · 5 SSO | — | $14.25 Pay as you go |
| 100k users · 10 SSO | — | $304.25 Pay as you go |
Cheapest verified plan per vendor, monthly USD list price. SSO users: Amazon Cognito, Supabase Auth and Firebase Auth / Identity Platform bill SAML/OIDC per SSO user, not per connection (first 50 free, then $0.015 per SSO user a month). Their SSO results here assume 200 SSO users per connection (5 connections = 1,000 SSO users). See how 1,000 or 2,000 per connection changes the result or set your own. How we calculate this.
Auth0 paid plans: published MAU tiers (monthly / yearly)
| MAU up to | Essentials (B2C) | Professional (B2C) | Essentials (B2B) | Professional (B2B) |
|---|---|---|---|---|
| 500 | $35/mo $385/yr | $240/mo $2,640/yr | $150/mo $1,650/yr | $800/mo $8,800/yr |
| 1,000 | $70/mo $770/yr | $240/mo $2,640/yr | $300/mo $3,300/yr | $800/mo $8,800/yr |
| 2,500 | $175/mo $1,925/yr | $545/mo $5,995/yr | $700/mo $7,700/yr | $1,200/mo $13,200/yr |
| 5,000 | $350/mo $3,850/yr | $1,000/mo $11,000/yr | $1,300/mo $14,300/yr | $1,500/mo $16,500/yr |
| 7,500 | $525/mo $5,775/yr | $1,200/mo $13,200/yr | $1,725/mo $18,975/yr | $1,800/mo $19,800/yr |
| 10,000 | $700/mo $7,700/yr | $1,600/mo $17,600/yr | $2,100/mo $23,100/yr | $2,400/mo $26,400/yr |
| 20,000 | $1,400/mo $15,400/yr | $3,200/mo $35,200/yr | $3,800/mo $41,800/yr | Contact sales |
| 30,000 | $2,100/mo $23,100/yr | Contact sales | Contact sales | Contact sales |
| 40,000 | $2,800/mo $30,800/yr | Not available | Contact sales | Contact sales |
| 50,000 | $3,500/mo $38,500/yr | Not available | Contact sales | Contact sales |
Usage between tiers is billed at the next tier up. Above the last tier: Enterprise, contact sales. Source: auth0.com/pricing.md, checked 2026-10-31.
Auth0
Free to 25k MAU with 1 Enterprise Connection, Self-Service SSO and inbound SCIM. B2C Essentials runs $35 (500 MAU) → $700 (10k) → $3,500 (50k)/mo; B2C Professional $240 → $1,600 (10k) → $3,200 (20k). B2B Essentials $150 (500) → $2,100 (10k) → $3,800 (20k) with 3 SSO connections; B2B Professional $800 → $2,400 (10k) with 5. Extra SSO connections $100/mo. Yearly = 11× monthly. Above those tiers: Enterprise, contact sales.
Source: auth0.com/pricing · 2026-10-31
Firebase Auth / Identity Platform
No cost up to 50k MAU (email, phone, anonymous, social), then $0.0055/MAU to 100k, $0.0046 to 1M, $0.0032 to 10M, $0.0025 above. SAML/OIDC: 50 MAU free then $0.015/MAU. SMS (phone sign-in and MFA) billed per message by region (US $0.01); first 10 SMS a day not billed. Sources: cloud.google.com/identity-platform/pricing and firebase.google.com/pricing.
Source: cloud.google.com/identity-platform/pricing · 2026-10-31
Also see: Auth0 alternatives · Firebase Auth / Identity Platform alternatives · all vendors by MAU · vs self-hosting (Better Auth / Auth.js)
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