Authentication and user management · Comparison
Auth0 vs Clerk vs Supabase Auth: Supabase Auth leads at 9.3, with 100,000 users for $25
We read the pricing, security and docs pages of three authentication services on the same day and scored them on the same six indicators. What each one sells, what 10,000 users and five SSO connections cost, and who should pick which.
On this page8 sections
On six indicators read from each vendor's public pages, Supabase Auth scores 9.3, Clerk 8.2 and Auth0 6.8 out of 10. Supabase Auth includes 100,000 monthly active users on its $25 Pro plan, prices SAML SSO per user, and puts SOC 2, ISO 27001 and a HIPAA BAA on its self-serve Team plan. Clerk has the largest free allowance (50,000 retained users per app) with bot and breached-password protection on it. Auth0 scores lowest here, mainly on price at 10,000 users ($700 a month) and the cost of extra enterprise connections; it also has the broadest compliance list and six hosting regions.
The scores measure what the public pages commit to, not sign-in UX, developer experience or uptime, and we did not sign up for any of the three.
At a glance
| Auth0 | Clerk | Supabase Auth | |
|---|---|---|---|
| What you pay for | Audited identity, six data regions | Prebuilt sign-in UI, billing on retained users | Low per-user price inside a Postgres platform |
| Free tier | 25,000 MAU | 50,000 MRU per app | 50,000 MAU; paused after a week inactive |
| Entry paid plan at 10,000 users | $700 (B2C Essentials) | $25 (Pro) | $25 (Pro) |
| Enterprise SSO | 1 connection free; 3 on B2B Essentials, more from $100/mo | 1 on Pro, then $75/mo each | 50 SSO users on Pro, then $0.015 each |
| SOC 2 Type 2 report | From the Support Center | Business plan ($300/mo) | Team plan ($599/mo) |
| ISO 27001 | Yes | No | Yes |
| HIPAA BAA | Enterprise | Enterprise | Team, paid add-on |
| Data region | AU, CA, EU, JP, UK or US | US only | 17 AWS regions, EU included |
| Score (public pages) | 6.8 Good | 8.2 Excellent | 9.3 Excellent |
What the public pages show
Auth0, part of Okta, prices paid plans by monthly active users on a selector, separately for B2C and B2B. Free covers 25,000 users with no card to sign up. B2C Essentials starts at $35 for 500 users and reaches $700 at 10,000; past 30,000 the page says to get in touch. The docs describe annual SOC 2 Type 2 and ISO 27001/27017/27018 audits, and tenants in Australia, Canada, Europe, Japan, the UK or the US. A HIPAA BAA comes with an Enterprise subscription.
Clerk bills retained users, who count once they return a day or more after signing up. Hobby is free for 50,000 per app; Pro is $25 a month ($20 billed annually) with 50,000 included, then $0.02 each. Its security page lists SOC 2 Type 2 and HIPAA since May 2022, and says plainly that Clerk is not ISO 27001 certified and hosts data in the US only.
Supabase Auth comes with a Supabase project and stores users in the project's Postgres database. Free includes 50,000 users; Pro ($25, with $10 of compute credit) includes 100,000, SAML SSO priced per SSO user and leaked-password protection. The security page lists SOC 2 Type 2, ISO 27001 and HIPAA; Team customers ($599 a month) get the documents and can request a BAA in the dashboard. Projects run in the AWS region you choose.
Strengths and things to know
Auth0. Strengths: the broadest compliance list (adding CSA STAR and PCI deployment options), six hosting regions, and an enterprise connection, passkeys and brute-force protection on the free plan. Things to know: paid prices rise with users, SSO on paid plans needs a B2B plan, and breached-password detection (Professional) and bot detection (Enterprise add-on) sit on higher tiers.
Clerk. Strengths: the largest free allowance, bot protection, lockout and breached-password checks on every plan, published SSO prices, and full data exports. Things to know: US-only hosting, no ISO 27001, the SOC 2 report on the $300 Business plan, and MFA and passkeys from Pro.
Supabase Auth. Strengths: 100,000 users for $25, SSO priced by user, a self-serve route to a BAA, region choice, and users in your own Postgres. Things to know: free projects pause after a week of inactivity, the compliance documents start on Team, passkeys are experimental, and the pricing page describes Team's dashboard SSO in two different ways.
Pricing reality
All three charge by users but count differently: Auth0 and Supabase count monthly active users, Clerk counts retained users, which its pricing page says is often lower than raw MAU. These are list prices at the same user count, not identical bills.
| Service | Plan | Monthly cost at 10,000 users | Where the number comes from |
|---|---|---|---|
| Auth0 | B2C Essentials | $700 | Listed: price selector at 10,000 |
| Clerk | Pro | $25 | Listed: 50,000 MRU included |
| Supabase Auth | Pro | $25 | Listed: 100,000 MAU included |
Each free plan also covers 10,000 users; the rubric uses the paid plan, where MFA (Auth0, Clerk) or leaked-password protection (Supabase) starts.
SSO for five enterprise customers, computed from listed rates with 100 SSO users in all: Auth0 needs B2B Essentials, $2,100 at 10,000 users with 3 connections, plus 2 from $100 each, so $2,300 or more (B2B Professional with 5 included is $2,400). Clerk is $25 plus 4 connections at $75, or $325. Supabase Auth is $25 plus 50 SSO users at $0.015, or $25.75.
At 100,000 users, also computed: Supabase Pro stays at $25; Clerk Pro is $25 plus 50,000 retained users at $0.02, or $1,025; Auth0's selector stops at 30,000 ($2,100 on B2C Essentials).
How we scored them
Every product in this category is scored on the same six indicators with fixed formulas; the overall score is the plain mean. Our methodology page explains how these scores work.
| Indicator | Auth0 | Clerk | Supabase Auth |
|---|---|---|---|
| Pricing clarity | 8 | 10 | 9 |
| Free tier | 9.4 | 10 | 9 |
| Price at 10,000 users | 2.8 | 10 | 10 |
| Enterprise SSO | 4.3 | 5.1 | 9 |
| Compliance documents | 9 | 5 | 10 |
| Security on self-serve plans | 7 | 9 | 8.5 |
| Overall | 6.8 | 8.2 | 9.3 |
Auth0's lowest items are price at 10,000 users and SSO, where moving to a B2B plan adds about $1,600 a month in our reference case; pricing clarity loses 2 because self-serve prices stop at 30,000 users. Clerk loses on compliance (no ISO 27001, no region choice) and on the $300 that five connections add. Supabase Auth loses a point for pausing free projects, one for the dashboard-SSO statements that do not match, and 1.5 on security for experimental passkeys and leaked-password protection from Pro.
The rubric rewards what a buyer can confirm before signing up. It has no item for prebuilt UI components, Clerk's clearest difference, or for Auth0's extensibility, FAPI certification and private cloud, and it cannot see support quality, uptime or daily SDK use. Hands-on runs will add that evidence later.
Who should choose which
- Choose Supabase Auth if you build on Supabase, expect many users, or need EU hosting and a self-serve route to a BAA. Look elsewhere if you need production passkeys today.
- Choose Clerk if you want prebuilt sign-in screens, a free plan that does not pause, and SSO at published prices. Check whether US-only hosting fits your customers.
- Choose Auth0 if customers ask for ISO 27001, data in a non-US region, or a path to private deployment. Price the plan at your user count first.
Bottom line
From public pages alone, Supabase Auth is the least expensive per user and the most complete compliance package on a self-serve plan, and Clerk offers the largest free allowance with clear prices. Auth0 is the pick when audited compliance, region choice and enterprise depth matter more than price per user; its lower score reflects what this rubric counts, not how well its login works.
How we checked
We read the vendors' pricing, security and documentation pages on Oct 15, 2026, including Auth0's price selector at each step. We did not sign up or call an API. Facts the pages did not state, such as whether Supabase asks for a card or which Auth0 plan unlocks the SOC 2 download, are left out rather than guessed. Every figure is on the vendors' pages as of that date or computed from them as shown.
