Authentication and user management · Comparison
Auth0 vs Clerk vs Firebase Authentication vs Supabase Auth
4 products compared side by side: what you pay for with each one first, then the five access facts, entry prices, recorded plan limits and the bottom line of each review. The evidence note under the table says how each product was checked.
Side by side
| Metric | Auth0 | Clerk | Firebase Authentication | Supabase Auth |
|---|---|---|---|---|
| What you're paying for | Compliance includedAudited enterprise identity — SOC 2 Type 2, ISO 27001 and six hosting regions — with a free plan of 25,000 users and one enterprise connection. | Saves engineering timeReady-made sign-in and user management, free for 50,000 retained users, with SSO and MFA from $25 a month at published prices. | Worth the priceSign-in that plugs into Firebase and Google Cloud, free to 50,000 monthly users, with SAML at $0.015 per user and a self-serve Google Cloud BAA. | Worth the price100,000 monthly active users on the $25 Pro plan, SSO priced per user, and SOC 2, ISO 27001 and a HIPAA BAA on the self-serve Team plan. |
| Overall score | 6.8 | 8.2 | 8.4 | 9.3Best |
| Free option | Free plan | Free plan | Free plan | Free plan |
| Card to start | No card needed | No card needed | No card needed | –Not measured |
| Getting access | Self-serve | Self-serve | Self-serve | Self-serve |
| Starter priceCheapest paid plan | $35/mo | $25/mo | $0.0055/MAU above 50,000 | $25/mo |
| Pricing model | Tiered | Usage-based | Usage-based | Usage-based |
| Pricing page | Public prices | Public prices | Public prices | Public prices |
| Free plan | 25,000 MAU, no card to sign up | 50,000 MRU per app, no card | 50,000 MAU; Spark capped at 3,000 a day | 50,000 MAU; paused after 1 week inactive |
| Entry paid plan at 10,000 users | $700/mo (B2C Essentials) | $25/mo (Pro), $20 billed annually | $0 (Blaze), 50,000 MAU at no cost | $25/mo (Pro), 100,000 MAU included |
| Enterprise SSO | 1 connection free; 3 on B2B Essentials, more from $100/mo each | 1 connection on Pro, then $75/mo each | 50 SAML/OIDC users free on Blaze, then $0.015 each | 50 SSO users on Pro, then $0.015 each |
| SOC 2 report | Type 2, from the Support Center | Type 2, on Business ($300/mo) | SOC 2 (Google), via Compliance Reports Manager | Type 2, on Team ($599/mo) |
| HIPAA BAA | With an Enterprise subscription | Enterprise plan | Google Cloud BAA, accepted in the console | Team plan, paid add-on |
| Data region | AU, CA, EU, JP, UK or US per tenant | US only | US only | 17 AWS regions, EU included |
| Log retention on the entry paid plan | 5 days (Essentials) | 7 days of application logs (Pro) | 30 days in Cloud Logging (activity logs, opt-in) | 7 days of auth audit logs (Pro) |
| Bottom line | From its public pages, Auth0 is the most complete compliance and data-region package of the three, with a generous free plan. Its paid plans cost more per user than the others, so price the B2C or B2B plan at your user count first. | From its public pages, Clerk offers the largest free allowance here and clear prices from the first user to SSO. Check US-only hosting and the plan that unlocks the SOC 2 report against your customers’ requirements. | From its public pages, Firebase Authentication is the least expensive route here to SAML SSO and a self-serve BAA, inside the Firebase platform. Check US-only processing and the protections it does not list. | From its public pages, Supabase Auth is the least expensive per user of the three and the only one with a BAA on a self-serve plan. It fits best when the rest of your app runs on Supabase. |
Evidence: Auth0: facts checked 2026-10-15 from its public sign-up and pricing pages, no completed hands-on run; Clerk: facts checked 2026-10-15 from its public sign-up and pricing pages, no completed hands-on run; Firebase Authentication: facts checked 2026-10-15 from its public sign-up and pricing pages, no completed hands-on run; Supabase Auth: facts checked 2026-10-15 from its public sign-up and pricing pages, no completed hands-on run. Prices in USD as listed, excluding tax. "–" means not recorded.
When to pick each
In the words of each review, with the date its facts were checked.
From our Auth0 review
Checked Oct 15, 2026- Pick Auth0 when
- You need ISO 27001, a non-US hosting region, or an enterprise connection on the free plan.
- Pick Clerk when
- You want 10,000 users for $25 a month, published SSO prices from $75 a connection, and bot protection on the free plan.
From our Auth0 review
Checked Oct 15, 2026- Pick Auth0 when
- You want a dedicated identity platform with six regions, CSA STAR and PCI options, and enterprise features such as private deployment.
- Pick Supabase Auth when
- You want 100,000 users on a $25 plan, SSO priced per user, and a HIPAA BAA on a self-serve plan.
From our Clerk review
Checked Oct 15, 2026- Pick Clerk when
- You want 10,000 users for $25, SSO connections from $75 each, and bot and breached-password protection on the free plan.
- Pick Auth0 when
- You need ISO 27001, data hosted outside the US, or an enterprise connection on a free plan.
From our Clerk review
Checked Oct 15, 2026- Pick Clerk when
- You want prebuilt sign-in UI and billing that skips users who never return.
- Pick Supabase Auth when
- You need an EU hosting region, ISO 27001, or a HIPAA BAA without an enterprise contract.
From our Firebase Authentication review
Checked Oct 15, 2026- Pick Firebase Authentication when
- You build on Firebase or Google Cloud and want a BAA you accept in the console rather than on a $599 Team plan.
- Pick Supabase Auth when
- You need an EU hosting region, passkeys, leaked-password protection, or users stored in your own Postgres database.
From our Firebase Authentication review
Checked Oct 15, 2026- Pick Firebase Authentication when
- You want ISO 27001, a self-serve BAA and SSO priced per user rather than $75 per extra connection.
- Pick Clerk when
- You want prebuilt sign-in UI with bot protection and breached-password checks on the free plan.
From our Supabase Auth review
Checked Oct 15, 2026- Pick Supabase Auth when
- You want 100,000 users on a $25 plan, SSO priced per user, and a HIPAA BAA without an enterprise contract.
- Pick Auth0 when
- You want a dedicated identity platform with private deployment, CSA STAR and PCI options, and passkeys that are not experimental.
From our Supabase Auth review
Checked Oct 15, 2026- Pick Supabase Auth when
- You need an EU hosting region, ISO 27001, or users stored in your own Postgres database.
- Pick Clerk when
- You want prebuilt sign-in UI, a free plan that never pauses, and billing that skips users who do not return.
Entry price
Baseline: each product's cheapest paid plan, per month. Included usage differs, so read the line under each price.
- Auth0Essentials (B2C)$35/mo500 MAU; $700 at 10,000, $2,100 at 30,000
- Pro MFA (OTP, Duo)
- 5-day log retention
- Standard support
- ClerkPro$25/mo50,000 MRU per app, then $0.02 each (50,001–100,000); $20/mo billed annually
- MFA and passkeys
- 1 SSO connection, then $75/mo each
- 7-day application logs
- Email support
- Firebase AuthenticationBlaze$0.0055/MAUAfter 50,000 free MAU; $0.0046 from 100,000, $0.0032 from 1M, $0.0025 from 10M
- SAML/OIDC: 50 MAU free, then $0.015 each
- Phone sign-in and SMS MFA billed per SMS ($0.01 in the US)
- First 10 SMS a day not billed
- Identity Platform SLA
- Supabase AuthPro$25/moFrom $25; 100,000 MAU, then $0.00325 per MAU
- SAML SSO: 50 SSO users, then $0.015 each
- Leaked password protection
- 7-day auth audit logs
- Email support
Prices as listed on each pricing page, in USD per month, excluding tax. Observed: Auth0 2026-10-15, Clerk 2026-10-15, Firebase Authentication 2026-10-15, Supabase Auth 2026-10-15.
Which one fits
- If you need to start today without a sales call
- Supabase AuthSelf-serve sign-up; the highest score of the 4 self-serve products here (9.3/10).
- If you want to try it without entering a card
- Firebase AuthenticationFree plan, no card needed, and the highest score of the 3 that skip the card (8.4/10).
- Lowest starter price
- Clerk and Supabase Auth$25/mo for the Pro plan each. Firebase Authentication lists no comparable paid price.
- Highest overall score
- Supabase Auth9.3/10 (Excellent). The review shows the score breakdown and the run behind it.
Picked by fixed rules from the table above, not by hand. How we score