Better Auth vs Clerk vs Supabase Auth for a Mexican SaaS (2026): The Honest Decision
For a new Mexican SaaS in 2026, pick Better Auth if you want a TS-native library that owns your users in your own Postgres with first-class multi-tenancy (but patch CVE-2025-61928 first). Pick Supabase Auth if you're already on Supabase and want RLS doing half your authorization. Choose Clerk only when fastest DX justifies the cost and US-only data residency is acceptable.
Which auth provider should a 2026 LATAM SaaS pick?
For a new SaaS in 2026 it’s a two-horse race — Better Auth or Supabase Auth — with Clerk off to the side as the pay-for-speed option. My verdict from Puebla: lean Better Auth (own-your-Postgres, multi-tenant) or Supabase Auth (if you’re already on it and want RLS). Clerk buys speed, but at a higher bill and with US-default data.
That’s a shift from a few years ago, when “just use the hosted thing” was the default. Here’s how I frame the three from my desk:
- Better Auth is a TypeScript-native auth library. Your users live in your OWN Postgres, and it ships first-class multi-tenancy — which matters a lot for B2B SaaS where every customer is a tenant.
- Supabase Auth is the best pick if you’re already on Supabase and want Row Level Security (RLS) doing half your authorization. Auth is wired into the same Postgres your data already lives in.
- Clerk is hosted, has the fastest developer experience, but it’s pricier and stores data in the US by default.
For a Mexican or LATAM SaaS specifically, the axes that actually move the decision aren’t the ones the launch blogs obsess over. They’re: data residency (where your user data physically lives), cost at scale, multi-tenancy, and — the one nobody likes to talk about — who owns patches and breach response when something goes wrong.
Honest framing, labeled as opinion: there is no universal winner here. This is a trade of operational ownership versus outsourcing, full stop. The right answer depends on what you’re already running and how much of the operational surface you want to carry. The makerkit comparison walks the same three contenders if you want a second read — though published auth-pricing estimates vary by plan tier and MAU assumptions, so confirm every figure against each provider’s current pricing page before you budget.
Better Auth / Supabase
- Better Auth: your own Postgres, you pick the region — real MX/LATAM data residency
- Supabase: data residency follows your project region
- Better Auth: first-class multi-tenancy built in
- Supabase Pro includes 100k MAU at ~$25/mo base (as of 2026, confirm current)
- You own the operational surface (more so with Better Auth)
Clerk
- Hosted, fastest DX — you outsource ops
- US data by default; EU residency on higher tiers (as of 2026)
- ~$1,025/mo at 100k MAU (as of 2026, confirm current)
- Pricing has been revised more than once recently
- Breach response and patches are on the vendor
Should you use Better Auth for a LATAM SaaS?
Better Auth is a TypeScript-native auth library, not a hosted service. That distinction is the whole point: your users live in your own Postgres, alongside the rest of your data. There’s no third party holding your user table.
For B2B SaaS, the feature I care about most is its first-class multi-tenancy. When each customer is a tenant, you want tenant isolation baked into the auth model rather than bolted on later. Better Auth treats that as a first-class concern.
A tiny illustrative shape of the own-your-Postgres, multi-tenant model:
// Illustrative: multi-tenant user shape in your own Postgres
// (schema sketch, not Better Auth's exact API)
type User = {
id: string;
email: string;
tenantId: string; // every user belongs to a tenant
role: "owner" | "admin" | "member";
};
// Authorization always scopes by tenant — never trust a bare userId
function canAccess(user: User, resourceTenantId: string) {
return user.tenantId === resourceTenantId;
}Now the honest part. Better Auth ships rate limiting, but rate limiting in a library is not a WAF — you still need an IP-aware edge layer in front of it. And self-hosting means you own the operational surface: you own patches, you own breach response, you own the 2 a.m. page. That’s a cost, not just a benefit, and I’ll say it plainly because the marketing usually doesn’t.
The upside of all that ownership is data residency. With Better Auth, your data residency is simply whatever region your Postgres sits in. If you need to keep user data in Mexico or somewhere specific in LATAM, that’s a real, concrete advantage — you control it directly instead of asking a vendor what region they happen to use.
Is Better Auth safe after CVE-2025-61928?
I won’t recommend Better Auth without naming this. In 2025, Better Auth shipped CVE-2025-61928: unauthenticated API-key creation via the api-key plugin. The authorization logic was flawed in a way that let an attacker pass a userId in the request body and skip authentication entirely.
The severity was critical — it enabled account takeover. It was patched in version 1.3.26.
I’m not raising this to scare you off. I’m raising it because it’s exactly the kind of thing you sign up to own when you self-host. A bug like this fairly raises questions about the maturity of the project’s security review, and for a self-hosted library where YOU own breach response, that’s not academic. If the CVE had hit your production deployment, nobody else was patching it for you.
The operational takeaway:
- Pin a recent version — at minimum 1.3.26 or later, and watch advisories from there.
- Rotate any API keys that could have been created during the exposure window.
- Review your auth surface before you trust it, instead of assuming a library handled it.
This is the work you own with self-hosting. If that sentence makes you uneasy, that’s useful information about which option fits you. The advisory is public — search “Better Auth CVE-2025-61928” to read the full write-up.
Does Supabase RLS replace your authorization layer?
Supabase Auth wins cleanly in one situation: you’re already on Supabase. When that’s true, auth is wired into the same Postgres your data lives in, and you avoid the tax of stitching two systems together and keeping their user identities in sync.
The real superpower here is Row Level Security. RLS can do roughly half your authorization work at the database layer, which means fewer authorization bugs leaking out of your application code. The database itself refuses to return rows the current user shouldn’t see.
A sketch of what that looks like:
-- Illustrative RLS policy: users only see their own tenant's rows
alter table projects enable row level security;
create policy "tenant_isolation"
on projects
for select
using ( tenant_id = (auth.jwt() ->> 'tenant_id')::uuid );That using clause runs on every query — your app code can’t accidentally forget it.
On cost: Supabase’s Pro plan runs ~$25/mo base and includes 100,000 MAU, with auth overage of $0.00325 per MAU only beginning ABOVE 100k (as of 2026 — verify current before you commit). So at exactly 100k MAU your auth is inside the included quota, not a separate line item. Data residency depends on your Supabase project region, so check that it supports the locality you actually need before you assume it does.
And tie this back to the bigger picture: auth is the gate, but RLS plus your entitlements layer is what actually unlocks features per plan and per tenant. RLS handles “can this user see this row.” Entitlements handle “does this user’s plan include this feature.” Those are different jobs.
How much does Clerk cost at 100k MAU?
Clerk is genuinely good at what it does. It’s hosted, the developer experience is the fastest of the three, and you outsource the entire operational surface — patches, breach response, infrastructure. When you’re racing to product-market fit and want to not think about auth at all, that’s a real value.
Now the three downsides that matter for a Mexican SaaS.
First, cost. Clerk’s Pro plan includes 50,000 free monthly users, then charges $0.02 per user above that. At 100,000 MAU that works out to roughly $25 base plus 50,000 × $0.02, or about $1,025/mo (as of 2026 — verify current on clerk.com/pricing). Set that next to Supabase’s ~$25/mo base — which includes 100k MAU — and the gap is enormous. That’s not a rounding error in a financial model.
Second, pricing stability. Clerk has revised its pricing more than once recently — the free tier alone moved from 10,000 to 50,000 monthly users. If you’re modeling costs out a few years ahead — which you should be for any SaaS — that’s a planning risk, because the number you budget today may not be the number you pay later.
Third, and most important for us: Clerk stores user data in the US by default, with EU data residency available only on higher tiers as of 2026. That’s a real data-residency and GDPR consideration, and worth weighing for LATAM data residency too. If you have a reason — legal, contractual, or strategic — to keep user data in a specific region, you’ll want to confirm Clerk offers that lever on the tier you can afford, and remember a US-headquartered vendor still carries US sovereignty exposure even with EU residency.
My labeled opinion: Clerk is great for shipping fast to PMF. The common pattern I see is teams migrating off it somewhere around the 50k-MAU mark, when the monthly bill finally catches an engineer’s attention.
Figures are at 100,000 MAU as of 2026 — verify current. Supabase Pro’s ~$25/mo base already includes 100k MAU; Better Auth is a free library, so you pay only your own database hosting.
Why is auth the gate and entitlements what it unlocks?
Whichever provider you pick, internalize this: auth only proves WHO the user is. It does not decide WHAT they can do. Those are two different layers, and conflating them is how authorization bugs are born.
Entitlements — the user’s plan, role, and tenant limits — are a separate layer you own regardless of the auth provider. Better Auth, Supabase, Clerk; none of them decides whether this user’s plan includes the export button. That’s your code.
With Supabase Auth, RLS can enforce part of this in the database. With Better Auth or Clerk, you wire entitlements in application code. Either way, the entitlements logic is yours.
The practical advice I’d give my past self: keep the entitlements layer provider-agnostic. Don’t let Clerk’s SDK or Supabase’s RLS leak into how you express “what this plan unlocks.” If you do it right, a future migration — say Clerk to Better Auth when the bill gets loud — doesn’t force you to rewrite your whole authorization model. You swap the gate; the thing it unlocks stays put. Once you have authed users, wiring billing and syncing that state reliably is the next layer.
How do you pick in 30 seconds?
No flowchart needed. Match your situation to one of these three paths.
- Already on Supabase + want RLSSupabase Auth — Pro ~$25/mo base includes 100k MAU (as of 2026). Let RLS carry half your authorization.
- Want own-Postgres + multi-tenant + TS-nativeBetter Auth. Patch CVE-2025-61928 to 1.3.26 or later first, then own your operational surface.
- Need fastest DX + can pay + US-default data is OKClerk (~$1,025/mo at 100k MAU, as of 2026). Buy speed, accept US-default data.
For most MX and LATAM SaaS, I lean Better Auth or Supabase Auth — and I’ll label that as opinion. Clerk buys you speed at a cost, plus US-default data, and for our region that data-residency point is rarely something I want to give up. But the honest limit stands: this is a trade of operational ownership versus outsourcing, not a one-size answer.
FAQ
Is Better Auth safe to use after the CVE? It was patched in version 1.3.26. The real lesson isn’t “Better Auth is unsafe” — it’s that self-hosting means you own patching and breach response. Pin a recent version and watch advisories. If that ongoing responsibility isn’t a fit for your team, that tells you something.
Can I use Clerk from Mexico? Yes, technically — it works fine. But your user data sits in a US database by default as of 2026, with EU residency only on higher tiers. Weigh that for data residency and GDPR before you commit, especially if you have legal or contractual reasons to keep data in-region.
Does Supabase Auth replace my authorization layer? No. RLS does part of it at the database layer, but you still own entitlements — plan limits, roles, feature gating. Auth and entitlements are different jobs.
What’s cheapest at 100k MAU? Better Auth, because it’s a free library and you pay only your own database hosting. Then Supabase, whose ~$25/mo Pro base already includes 100k MAU, then Clerk at ~$1,025/mo (all as of 2026 — verify current).
What about tax and PII storage law? I’m an engineer, not a contador. Where you must store PII for tax or privacy law is a question for a real advisor. I can tell you how the data residency works technically; I can’t tell you what your compliance obligations are.
You can find more SaaS-engineering guides on my integrations page.
The honest closing
There’s no universal winner. Pick by the four axes that actually matter for a Mexican SaaS: where user data lives, cost at scale, multi-tenancy, and who owns breach response when it goes wrong.
For a new MX or LATAM SaaS in 2026, I lean Better Auth or Supabase Auth — labeled opinion, and yours may differ based on what you’re already running. Clerk earns its place when speed to PMF outweighs the bill and its US-default data residency.
And every price in here is as of 2026 — verify the current numbers before you sign anything. Pricing moves, and Clerk’s especially.