Will Firebase pricing actually surprise me?

Yes, if traffic patterns shift. Firestore bills per document read, and naive query patterns can cause read amplification (one user action triggers dozens of reads). Supabase Postgres bills per database size + connection time, which is easier to model. Both reward thoughtful schema design.

Can I migrate from Firebase to Supabase later?

Possible but expensive. The schema shape is different (documents vs rows), the SDKs are different, and any client code that uses Firestore real-time listeners has to be rewritten. Plan the migration as 4-8 weeks for a typical small SaaS. Better to pick correctly the first time.

What about Convex, Neon, PlanetScale, Turso?

Convex is the most credible Firebase alternative on the new-stack side; we have built one production app on it and like it for document-shaped products. Neon and Turso are Postgres-only (no auth, no storage) — pair them with Clerk + S3 if you want à-la-carte. PlanetScale is MySQL-shaped; great if your team already runs MySQL.

Do you use Supabase for auth too?

No. We use Clerk for auth and Supabase only as the database + storage layer. Splitting them buys flexibility (we can switch databases without re-onboarding users) at the cost of one more SaaS bill. For a solo founder shipping fast, Supabase Auth is fine.

How do you handle row-level security on Supabase?

RLS policies on every table, service-role used only for trusted server-side writes, and a `tenant_id` column on multi-tenant data with a policy that filters by JWT claim. We treat RLS-off as a deploy-blocker.

Comparison · Supabase vs Firebase

Supabase vs Firebase: which backend for a new SaaS?

TL;DR

Pick Supabase when the data is relational (multi-tenant SaaS, anything with joins, anything where you might want SQL access later) and you want the option to walk away from the vendor with a Postgres dump. Pick Firebase when the data is document-shaped, real-time syncing is the core product experience (chat, presence, live collaboration), and you are already inside the Google ecosystem. For most B2B SaaS in 2026, Supabase is the safer default.

How they compare, dimension by dimension

Supabase versus Firebase (Firestore) — eight to nine dimensions that actually change the decision.

Dimension	Supabase	Firebase	Edge
Database model	Postgres (relational)	Firestore (document)	?
Real-time / sync	Postgres logical replication (good)	First-class (excellent)	→
Auth	Built-in (or BYO Clerk/Auth0)	Built-in	=
Storage / files	S3-style buckets	Cloud Storage	=
Edge functions	Deno-based, mature	Cloud Functions	=
Vendor lock-in	Low — open-source Postgres	High — Firestore-specific	←
Self-host option	Yes	No	←
Pricing predictability	Predictable per-row + per-GB	Per-read pricing can surprise	←
Hiring pool (SQL vs NoSQL)	Anyone who knows SQL	Smaller — Firestore-specific	←

When to pick which

Pick Supabase if

The data is relational — orders, line items, users, tenants, anything you would draw with foreign keys.
You want SQL access (analytics, BI tools, manual debugging).
You want the option to leave the vendor with a `pg_dump` and your code mostly intact.
You are integrating Clerk for auth and want the simpler split (Clerk for auth, Supabase for data).

Pick Firebase if

Real-time sync is the core experience (chat, multiplayer, live collaborative docs).
The data is genuinely document-shaped and joins are not a core access pattern.
Your stack is already Google Cloud + you want first-party billing and integration.
You need offline-first mobile sync — Firestore SDKs handle this better.

Our take

We ship production on Supabase. Trade Book Central and 90% of our client SaaS work runs on Postgres-via-Supabase, with Clerk for auth and Stripe for billing. We have not regretted the choice — the relational model wins more than it loses, and the day we hit a Supabase limit, the escape hatch is a Postgres database we already own. We would still pick Firebase for a real-time-first product like a presence-based collaboration tool. The choice is task-shaped, not religious.

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Common questions

Will Firebase pricing actually surprise me?: Yes, if traffic patterns shift. Firestore bills per document read, and naive query patterns can cause read amplification (one user action triggers dozens of reads). Supabase Postgres bills per database size + connection time, which is easier to model. Both reward thoughtful schema design.
Can I migrate from Firebase to Supabase later?: Possible but expensive. The schema shape is different (documents vs rows), the SDKs are different, and any client code that uses Firestore real-time listeners has to be rewritten. Plan the migration as 4-8 weeks for a typical small SaaS. Better to pick correctly the first time.
What about Convex, Neon, PlanetScale, Turso?: Convex is the most credible Firebase alternative on the new-stack side; we have built one production app on it and like it for document-shaped products. Neon and Turso are Postgres-only (no auth, no storage) — pair them with Clerk + S3 if you want à-la-carte. PlanetScale is MySQL-shaped; great if your team already runs MySQL.
Do you use Supabase for auth too?: No. We use Clerk for auth and Supabase only as the database + storage layer. Splitting them buys flexibility (we can switch databases without re-onboarding users) at the cost of one more SaaS bill. For a solo founder shipping fast, Supabase Auth is fine.
How do you handle row-level security on Supabase?: RLS policies on every table, service-role used only for trusted server-side writes, and a `tenant_id` column on multi-tenant data with a policy that filters by JWT claim. We treat RLS-off as a deploy-blocker.