Auth for indie SaaS: what makers chose, and what it costs at 100k users
What 395 makers' products use for sign-in, why the libraries are hiding in the numbers, and what Clerk, Supabase, WorkOS, Firebase, Auth0 and Better Auth cost at 10k, 100k and 250k monthly users.
Published 2026-09-30 · numbers refreshed 2026-10-08 from the site's data · how evidence is collected
Sign-in is the first building block most products wire up, and the choice is really between two kinds of tool: a hosted service that owns your users and their sessions (Clerk, Auth0, WorkOS), or a library in your app that keeps users in your own database (Better Auth, Auth.js) — with backend platforms like Supabase and Firebase in between.
What makers' products show: hosted services, mostly Clerk
Clerk307 · 78%
Auth021 · 5%
WorkOS19 · 5%
Supabase13 · 3%
Kinde7 · 2%
PropelAuth7 · 2%
Better Auth6 · 2%Stytch5 · 1%Of the 395 makers' products that show their auth, 93% use a hosted service, and Clerk alone is in 307. Taken at face value, that says hosted auth has won.
What the code shows: the opposite
It hasn't — it's just easier to see. A hosted service loads its script on your sign-in page and appears in your subprocessor list; a library runs inside your server and leaves no trace on your website. Count the other way — open-source projects that declare the package in their code — and the picture flips:
| Makers' live products | Open-source projects' code | |
|---|---|---|
| Clerk | 307 | 11 |
| Auth0 | 21 | 17 |
| WorkOS | 19 | 11 |
| Supabase | 13 | 0 |
| Better Auth | 6 | 94 |
| Auth.js | 0 | 57 |
Better Auth appears in 94 open-source projects against Clerk's 11. And its downloads grew 8.4× as fast as the median package we track over the last year — the fastest of any auth option — while Clerk's grew 1.5× and Auth.js's 0.9×. Supabase Auth is undercounted too: it comes with the Supabase project and rarely gets named separately.
Neither column is market share. Makers' products favour what's visible from outside; open-source projects favour libraries. Read them together.
What it costs as you grow
Free tiers make every option look the same at launch. They stop looking the same around 50,000 monthly active users. At list prices, from each vendor's pricing page:
| 10,000 MAU | 100,000 MAU | 250,000 MAU | |
|---|---|---|---|
| Better Auth | $0 | $0 | $0 |
| WorkOS | $0 | $0 | $0 |
| Supabase | $0 | $25 | $513 |
| Firebase | $0 | $275 | $965 |
| Clerk | $0 | $1,025 | $3,725 |
| Auth0 | $0 | over plan limits | over plan limits |
Better Auth's $0 is the library — your server and database pay for the users. WorkOS's user management is free into the millions; its business is enterprise SSO, charged per connection. Clerk's per-user pricing is the steepest at scale, which is the trade for its prebuilt UI, organizations and time saved on day one. Auth0's cheaper plans cap out below 100,000 users.
How to choose
- You want sign-in, profiles and teams working today, on Next.js or React: Clerk — and keep a user row in your own database, so moving later isn't a password reset for everyone.
- You're already on Supabase or Firebase: use its auth; it's tied to your data's access rules.
- You want users in your own database and no per-user bill: Better Auth, the fastest-growing option.
- You sell to companies that will ask for SAML SSO: WorkOS.