Clerk vs Auth0 vs Supabase Auth Pricing 2026 Compared

Clerk, Auth0 and Supabase Auth are the three options most founders weigh when adding sign-in to a 2026 product. Each meters users, but each includes a very different number of them, and one bundles auth into a larger backend platform. This article puts the verified free ceilings and per-user rates side by side and works the bill at four user counts. Prices were read from each vendor's own pricing page on 2026-10-11. For Clerk alone, see the Clerk pricing 2026 breakdown.

1. How big are the free tiers?

Provider	Free user ceiling	What free includes
Clerk (Hobby)	50,000 retained users per app[1]	Unlimited apps, prebuilt sign-in UI, up to 3 dashboard seats, 7-day fixed sessions
Auth0 (Free)	25,000 MAU[2]	Passwordless, unlimited social connections, 5 organizations, 1 custom domain
Supabase (Free)	50,000 MAU[3]	Auth bundled with a 500 MB database, 1 GB storage, 5 GB egress[4]

Clerk and Supabase both let a product reach 50,000 users before charging for auth; Auth0's free ceiling is half that. Two caveats change the picture. Supabase pauses free projects after one week of inactivity and allows two active projects, so a production app usually moves to Pro early^[4]. Clerk's free ceiling counts retained users rather than every active user, which stretches it further for products with many one-time sign-ups^[5].

2. Paid plans and per-user pricing

Provider	Paid base	Included users	Overage
Clerk Pro	$25/mo ($20 annual)[1]	50,000 MRU[1]	$0.02 (50,001-100,000), $0.018 (to 1M), $0.015 (to 10M), $0.012 above[1]
Auth0 B2C Essentials	$35/mo at 500 MAU[2]	Priced per user tier	Calculator: $700/mo at 10,000 MAU; custom above 30,000[2]
Supabase Pro	From $25/mo[3]	100,000 MAU[3]	$0.00325 per MAU[3]

Clerk Pro and Supabase Pro share a $25 starting price, but Supabase includes 100,000 users against Clerk's 50,000, and Supabase's overage of $0.00325 is about one-sixth of Clerk's first overage tier^[1][3]. Auth0 works differently: you choose a user tier, and every user in it is priced. B2C Professional starts at $240 a month for 500 MAU^[2]. Clerk's Business plan is $300 a month ($250 annually) and adds 10 dashboard seats and a SOC 2 report^[1].

3. Clerk's retained-user meter

Clerk bills on monthly retained users (MRU). A user counts as retained when they return 24 or more hours after signing up; someone who signs up and never comes back is not billed^[1][5]. For a product with heavy top-of-funnel sign-ups and modest retention, the billed count can sit well below the active-user count that Auth0 and Supabase meter. Clerk also gives a one-month grace period when returning users first push an app past 50,000 MRU^[5].

4. What does auth cost at four user counts?

Auth cost only, using each provider's published base and overage. Clerk figures assume every active user is also retained, which is the worst case for Clerk:

Users	Clerk	Auth0 (B2C Essentials)	Supabase
10,000	$0 (Hobby)[1]	$700/mo[2]	$0 (Free) or $25 Pro[3]
50,000	$0 (Hobby, at the cap)[1]	Custom quote (above 30,000)[2]	$25/mo Pro[3]
100,000	$25 + 50,000 × $0.02 = $1,025/mo[1]	Custom quote[2]	$25/mo Pro (at the cap)[3]
250,000	$25 + $1,000 + 150,000 × $0.018 = $3,725/mo[1]	Custom quote[2]	$25 + 150,000 × $0.00325 = $512.50/mo[3]

At 10,000 users Clerk and Supabase are free while Auth0 is already $700 a month. At 100,000, Supabase is still $25 and Clerk has reached $1,025. At 250,000, the gap is roughly seven to one in Supabase's favor^[1][3]. If half of Clerk's 250,000 actives were one-time sign-ups that never returned, its bill would fall to the 125,000-user figure of $1,475. Fold the chosen auth line into your full monthly stack with the AI stack cost calculator.

5. Bundled vs standalone auth

Price is not the only axis. Supabase Auth is bundled into the Supabase platform: the same Pro plan that covers 100,000 auth users also includes the Postgres database, 250 GB of egress, 100 GB of file storage and auto-generated APIs^[3]. If Supabase is already your backend, auth effectively rides on a plan you pay for anyway.

Clerk and Auth0 are standalone identity products. Clerk ships prebuilt sign-in, profile and organization components, and its Pro plan now includes one enterprise SSO connection per app^[1]. Auth0 brings deep enterprise identity features, such as enterprise MFA, custom token exchange and private deployment add-ons, that justify its price when you sell to large customers^[2].

6. Decision guidance

• Cheapest past 50,000 users: Supabase Auth. $25 a month includes 100,000 MAU; overage is $0.00325 per user.
• Already on Supabase for the database: use Supabase Auth; it is part of the plan you already pay for.
• Want prebuilt auth UI under 50,000 retained users: Clerk, free on Hobby, $25 a month when you need Pro features.
• Selling to enterprises that need advanced identity controls: Auth0, accepting the steepest price curve.
• Watch the overage: Clerk's $0.02 per user from 50,001 to 100,000 adds up quickly; Supabase's $0.00325 does not.

For B2B SSO pricing specifically, see WorkOS vs Clerk vs Stytch. For the full early-stage backend picture, see the 2026 AI solopreneur stack and Supabase vs Firebase vs Neon.

All pricing figures verified against official pricing pages on 2026-10-11.

Frequently asked questions

How much does Clerk auth cost in 2026?

Clerk's Hobby plan is free for up to 50,000 monthly retained users (MRU) per app. Pro costs $25 a month, or $20 a month billed annually, includes the same 50,000 MRU and adds $0.02 per extra retained user up to 100,000, then $0.018 to 1 million, $0.015 to 10 million and $0.012 beyond. Business is $300 a month ($250 annually). A retained user is one who comes back at least 24 hours after signing up, so one-time sign-ups do not count. Verified on clerk.com/pricing on 2026-10-11.

How much does Supabase Auth cost?

Supabase Auth is included in every Supabase plan. The Free plan covers 50,000 monthly active users, and the Pro plan, from $25 a month, includes 100,000 MAU and then charges $0.00325 per additional MAU. The same Pro plan also covers the Postgres database (8 GB disk per project), 250 GB egress and 100 GB file storage. Free projects pause after one week of inactivity, so production apps usually start on Pro.

Which auth provider is cheapest in 2026: Clerk, Auth0 or Supabase Auth?

For most solo and early-stage products, Supabase Auth is the cheapest once you pass 50,000 users, because its $25 Pro plan includes 100,000 MAU and charges only $0.00325 per user above that. Clerk is free up to 50,000 retained users and charges $0.02 per user from 50,001 to 100,000. Auth0 is free to 25,000 MAU, but its paid B2C Essentials plan prices every user once you upgrade, about $700 a month at 10,000 MAU on its own calculator.

Is Auth0 more expensive than Clerk and Supabase?

Yes, as soon as you leave the free plan. Auth0 B2C Essentials starts at $35 a month for 500 MAU and its pricing calculator shows $700 a month at 10,000 MAU; above 30,000 MAU the calculator routes you to a custom quote. Clerk and Supabase both include 50,000 or more users in a $25 plan. Auth0's pricing reflects its enterprise identity features rather than solo-founder economics.