Clerk vs Supabase Auth for Bootstrapped SaaS (2026)

Verdict: For a bootstrapped SaaS that already uses Supabase as its database, start with Supabase Auth: it is free to 50,000 monthly active users, includes basic MFA on every plan, and keeps users in your own Postgres where row level security can use them. Choose Clerk when polished hosted sign-in screens, organizations, invitations and B2B SSO matter more than one bill, and budget for Clerk Pro ($25/mo) once you need MFA or want Clerk's branding gone. If you want both, Clerk can sit in front of Supabase as a third-party auth provider.

Every price and limit below comes from the Clerk and Supabase pricing pages, checked on 7 Nov 2026. The advice in between is ours.

TL;DR#

• Free tiers look equal but are not. Clerk Hobby covers 50,000 MRUs (monthly retained users) per app (Clerk). Supabase Free covers 50,000 MAUs (monthly active users) (Supabase).
• MFA: not on Clerk Hobby; basic MFA included on Supabase Free. Supabase's advanced phone MFA is $75/mo for the first project.
• Pro plans: Clerk Pro is $25/mo ($20/mo annual) with 50k MRUs included, then from $0.02 per MRU. Supabase Pro is from $25/mo with 100,000 MAUs included, then $0.00325 per MAU.
• What you are buying: Clerk sells finished UI and B2B organizations. Supabase sells a Postgres database with auth and RLS built in.
• Free-tier catches: Clerk Hobby has a fixed 7-day session and Clerk branding. Supabase Free projects pause after a week of inactivity, with a limit of 2 active free projects.

Disclosure: ZeroRaised publishes this comparison and is a launch site for bootstrapped products. Facts come from the linked vendor pages as checked on 7 Nov 2026. ZeroRaised has no commercial relationship with Clerk or Supabase and earns nothing if you sign up.

Why this is a different question from "which free auth provider?"#

Our free auth providers roundup lines up the free tiers of ten vendors, from Auth0 to Cognito, so you can shortlist. This post assumes you have shortlisted two and plan to charge customers. That changes what matters. Free-tier user counts matter less than three things: where MFA and SSO sit on the price list, what the bill does as retained users grow, and whether you want your users table inside your own database or inside a vendor's dashboard.

Clerk vs Supabase Auth at a glance#

Sources: Clerk pricing, Supabase pricing. "Not covered" means the page we checked did not state it for this comparison, not that the feature is missing.

Counting users: MRU vs MAU#

The two free tiers both say 50,000, which tempts you to call it a draw. It is closer than most auth comparisons, but the units differ.

Clerk bills on monthly retained users. A user counts when they visit at least one day after signing up. Clerk calls this "First Day Free": someone who signs up, pokes around and never returns is not billed (Clerk). For a SaaS that gets launch-day spikes from Product Hunt or a Hacker News thread, that matters, because most of the tyre-kickers never become MRUs.

Supabase bills on monthly active users (Supabase). The pricing page we checked does not give a First Day Free style exemption, so plan on drive-by signups counting.

Our read: for a launch-heavy consumer app, Clerk's unit is kinder than the headline suggests. For a B2B SaaS where nearly every signup is a real account that comes back, the units converge and Supabase's larger Pro allowance does the talking.

What paid plans cost as you grow#

Both Pro plans start at $25/mo. The gap opens once you pass the included users. These examples apply only the listed rates. Clerk says "from $0.02" per extra MRU, so its real per-user price may fall at higher volumes; we use the starting rate. They also leave out Supabase compute beyond the included credits, SSO, phone MFA and add-ons.

First, the Supabase $25 is not an auth-only price. Supabase Pro includes your Postgres project, unlimited API requests and $10/mo of compute credits covering one Micro instance, and projects are not paused (Supabase). Clerk Pro is auth only, so you still need a database somewhere. Our free database hosting guide covers where that can live cheaply.

Second, 80,000 retained users is a good problem. If they pay you even a few dollars a month, $625 for auth is a small share of revenue. The real question for a bootstrapper is the first year, when you are well under 50,000 users and deciding whether to pay $25/mo at all. That decision mostly comes down to MFA.

MFA placement: the feature that forces the upgrade#

• Clerk: MFA is not on the Hobby plan. It arrives with Pro at $25/mo, or $20/mo billed annually (Clerk).
• Supabase: basic MFA is included on the plans, including Free. Advanced MFA with phone is an add-on at $75/mo for the first project (Supabase).

If you sell to businesses, expect MFA to come up early, often in a security questionnaire from your first serious customer. On Clerk that means you move to Pro the day someone asks. On Supabase you can tick the box on the free plan with basic MFA, and only pay $75/mo if a customer insists on SMS or phone factors.

Our read: if MFA is a hard requirement from day one and you want to stay at $0 for auth, Supabase Auth is the straightforward pick. If you were going to pay for Clerk Pro anyway for branding removal or SSO, MFA comes in the same $25.

SSO follows a similar pattern: Clerk Pro includes 1 SSO connection, while Supabase includes SAML/SSO for 50 MAU on Pro and above, then charges $0.015 per MAU. Model a large enterprise customer on both before you sign.

UI polish vs Postgres and RLS#

Clerk: finished screens and B2B plumbing#

Clerk ships prebuilt components for sign-up, sign-in and the user profile (Clerk). For a solo founder, that is days of form building, error states and password-reset flows you do not write. Clerk also has an organizations and roles story for B2B: teams, invitations and member roles, with 100 monthly retained organizations included and an Enhanced B2B add-on at $100/mo.

The trade-offs on the free plan are visible ones. Hobby keeps Clerk branding on those screens and fixes the session at 7 days. Pro removes branding and lets you set a custom session lifetime. If your SaaS is the kind where a "Secured by" badge on the login page bothers buyers, put Pro in the budget.

Supabase Auth: users in your own database#

Supabase Auth stores users in your Postgres database (Supabase). That is its biggest advantage, and it is about data rather than screens. Row level security (RLS) policies can refer to the signed-in user directly, so "users can only read rows they own" lives in the database, not in every API route. You can join users to your own tables and back them up with the rest of your data.

The trade-off is that you build more of the UI yourself, and team or organization features are something you model in your own tables. For a single-player tool or a simple per-user SaaS, that is not much work. For a multi-tenant B2B product with invitations and roles, it is real work that Clerk has already done.

Our read: choose by what you would otherwise have to build. If the hard part of your product is the data model and access rules, Supabase Auth plus RLS removes the most work. If the hard part is onboarding teams and looking credible to business buyers, Clerk removes more.

The free-tier catches that bite bootstrappers#

• Supabase pauses idle free projects. A Free project is paused after a week of inactivity, and you can have 2 active free projects (Supabase). Fine while you build; risky for a live product with quiet weeks. Pro projects are not paused, so move to Pro before you take money.
• Clerk Hobby is fine for production but looks free. The 50,000 MRU allowance is large, and Clerk allows unlimited apps and up to 3 dashboard seats on Hobby. The visible limits are branding, the fixed 7-day session and no MFA.

If you are mapping out your first-year costs more widely, our guide on how to bootstrap a SaaS shows where auth sits next to hosting, payments and email in the first 90 days.

When to combine Clerk and Supabase#

You can use both. Supabase documents third-party auth, and Clerk is one of the supported providers; both vendors publish guides for the integration. At a high level, Clerk handles sign-up, sign-in, sessions and organizations, and Supabase accepts Clerk's sessions so your database and RLS policies still know who the user is.

Combining makes sense when:

• you are already on Supabase for Postgres and storage, but your buyers are teams who need invitations, roles or SSO quickly
• you want Clerk's prebuilt UI without giving up RLS
• you started on Clerk with another database and are moving data to Supabase

It makes less sense when you are pre-revenue and every $25/mo counts. Running both means two vendors, two dashboards and two bills once you outgrow the free plans. Follow each vendor's current integration docs rather than a blog post, since setup details change.

Who should pick which#

Pick Supabase Auth if#

• Supabase is already, or will be, your database.
• You want auth, database and RLS on one $25/mo bill once you go Pro.
• You need MFA but do not want to pay for auth yet.
• You expect more than 50,000 active users within a year and want the larger included allowance.
• Your product is per-user rather than team-based, so you do not need ready-made organizations.

Pick Clerk if#

• You want polished sign-up, sign-in and profile screens without building them.
• You sell to teams and need organizations, roles and invitations soon.
• You expect launch spikes of one-time signups, which First Day Free does not bill.
• You will pay for Pro anyway for branding removal, MFA or an SSO connection.
• Your database lives somewhere other than Supabase.

Quick decision table#

Frequently asked questions#

Is Clerk or Supabase Auth cheaper for a bootstrapped SaaS?#

On the free plans they are close: Clerk Hobby covers 50,000 MRUs per app and Supabase Free covers 50,000 MAUs. On paid plans both start at $25/mo, but Supabase Pro includes 100,000 MAUs and the database, while Clerk Pro includes 50k MRUs and then charges from $0.02 per MRU. Past 50,000 retained users, Supabase Auth is usually the cheaper line item, though the units differ.

Does Clerk's free plan include MFA?#

No. Clerk's pricing page lists MFA as a Pro feature, not part of the free Hobby plan. Clerk Pro is $25/mo, or $20/mo billed annually. Supabase includes basic MFA on its free plan.

What is a monthly retained user in Clerk?#

Clerk bills on monthly retained users (MRU). A user counts when they come back at least one day after signing up. Clerk calls this First Day Free, so people who sign up once and never return are not billed.

Can I use Clerk and Supabase together?#

Yes. Both vendors document using Clerk as a third-party auth provider for Supabase. Clerk handles sign-up, sign-in and organizations, and Supabase stores your data and enforces row level security. You pay for both services, so it makes most sense when you need Clerk's UI or B2B features and already rely on Supabase for the database.

How is this different from ZeroRaised's free auth providers roundup?#

The free auth providers guide compares the free tiers of ten vendors side by side. This post goes deep on one decision, Clerk versus Supabase Auth, for a paying SaaS: what you get on paid plans, where MFA and SSO sit, what happens to costs as users grow, and when to run both.

Launch what you build#

ZeroRaised is a launch directory for products built without institutional VC. Once your sign-up flow is live, you can submit your product for free. For more guides on building and growing without investors, join the ZeroRaised newsletter.

Sources#

• Clerk pricing, last checked 7 Nov 2026
• Supabase pricing, last checked 7 Nov 2026