Convex vs Supabase

Q: Is Convex just Firebase with types?

- No. Firebase uses document-level listeners with no transactional joins. - Convex runs your query as a serialisable transaction, re-running when anything it read changes. - Convex also gives real ACID mutations across documents, which Firestore never has.

Q: Can I use Convex and Supabase together?

- Yes, some teams do: Supabase Postgres for reporting and analytics, Convex for the live surface. - It's more moving parts and a sync problem you now own. - Only do it with a concrete reason; most teams should pick one.

Q: Which is better for AI agents?

- Convex, in most cases. - Agents produce long-running jobs with state a UI must watch. - Convex's scheduled functions plus automatic subscriptions cover that without extra infrastructure. - Supabase can do it, but you'll add a queue, a worker and status streaming.

Q: Does Supabase lock me in at all?

- Less than most, but not zero. - The database is plain Postgres and moves cleanly. - Auth, Storage, Edge Functions and RLS style are the sticky parts. - Re-homing auth users is fiddliest: password hashes and provider identities.

Q: What about cost at scale?

- Supabase becomes a familiar, predictable compute-sizing exercise. - Convex becomes a query-shape exercise: costs scale with function calls and bandwidth. - A broadly scoped subscribed query over a hot table is what bites. - Both are cheap below serious traffic.

Q: Which has the better local development story?

- Supabase, narrowly: the CLI runs the whole stack in Docker with migrations in your repo. - That suits teams wanting deterministic CI. - Convex's dev deployment plus live push is a faster inner loop, but it's cloud, not local.

Choose Convex for a realtime-first, all-TypeScript stack that ships faster; choose Supabase for portable Postgres, SQL and extensions that are easier to leave.

Editorial judgement last reviewed 23 July 2026

Should I build on Convex or Supabase?

These are not the same product wearing different logos.
Supabase is Postgres with services bolted around it: auth, storage, edge functions, realtime, dashboard.
Convex is a reactive database where queries are TypeScript functions and every query is a live subscription.
One is infrastructure you rent; the other is a programming model you adopt.
On Supabase you write SQL and own a Postgres database.
On Convex you write query functions and own code that only runs on Convex.
Realtime, collaborative or agent-driven apps by small TypeScript teams: Convex is faster, fewer bugs.
No cache invalidation, no websocket layer, no hand-reconciled optimistic updates, no duplicated schema.
Transactions are real: functions run serialisably, a three-table query sees a consistent snapshot.
Data likely to outlive the app, analytics, reporting, an acquisition-shaped future: Supabase is safer.
Postgres is the most portable thing here; every BI tool, ORM and LLM speaks it.
Move the database to Neon, RDS, Hetzner or your own box in an afternoon.
Our score weights portability, so the two land closer than the marketing suggests.
Ignore the composite if your situation is lopsided: exit cost is huge at Series A, nothing at a weekend project.

Which one should you pick?

Choose Convex if…

Your UI is live: dashboards, chat, presence, collaborative editing, agent status.
You want subscriptions for free, without writing the invalidation logic that causes bugs.
Small, all-TypeScript team wanting end-to-end inference from schema to React hook.
No ORM layer to argue about.
You want crons, file storage, vector and full-text search without wiring four services.
You're building agent tooling: transactional functions plus scheduling show long jobs live.
You accept leaving means rewriting your data layer, trading exit cost for velocity.

Choose Supabase if…

You know SQL and want to keep it: window functions, CTEs, materialised views, EXPLAIN ANALYZE.
You need Postgres extensions: PostGIS, pgvector at scale, pg_cron, TimescaleDB workloads.
Portability is a requirement: compliance, procurement and acquirers ask where data lives.
You want row-level security enforced in the database, and you'll write RLS policies carefully.
Your stack isn't only TypeScript: Supabase has Python, Dart, Swift and Kotlin clients.
You want self-hosting on your own hardware as a fallback.

Reactivity: subscriptions by default vs subscriptions you configure

The biggest technical difference, worth stating precisely.
A Convex query is a TypeScript function that reads the database.
The runtime records which documents it touched and re-runs on any change.
You never say "invalidate this"; your React hook holds a correct live value.
Consistency is per-query and transactional: a three-table join can't return a half-updated view.
Supabase realtime is a different contract: it streams Postgres logical replication over a websocket.
You subscribe to a table with an optional filter and receive INSERT/UPDATE/DELETE events.
Powerful, but row-level, not query-level.
For derived values, counts, joins or aggregates, you translate "row changed" into "recompute this".
Most teams pair it with TanStack Query and hand-write invalidation rules.
For simple lists, both work fine.
For several interdependent derived values, Convex removes work Supabase makes you do.
No live surfaces at all: this section doesn't matter, decide on other axes.

Exit cost: the field nobody publishes

Exit cost, our killer field, scores how much application code a move requires.
It's the real question behind "should I use Convex", and no vendor answers it.
Leaving Supabase is close to a data migration.
Tables are Postgres tables; pg_dump produces a file that restores anywhere.
You leave behind auth users and hashed credentials, storage buckets, RLS policies and Edge Functions.
Real work, days to a couple of weeks, but the core asset moves intact.
Leaving Convex is a rewrite of the data layer.
Documents export cleanly; Convex doesn't hold your data hostage.
But queries, mutations, reactivity and crons are all Convex-specific and not portable.
You rewrite to Postgres plus an ORM plus a realtime story plus a job runner.
Exit cost is a real liability, and frequently the right trade.
Shipping six months earlier buys runway to afford a later migration.
Just make the trade deliberately.

Pricing shape, and where each one surprises you

Supabase prices like infrastructure: flat platform fee per project, compute by instance, plus storage and egress.
Predictable and easy to model on a spreadsheet.
Surprises: paused free projects need restoring; compute is the line item that grows; media bandwidth adds up.
Convex prices like a platform: function calls, action compute, database bandwidth and storage.
Generous free tier that carries a real side project comfortably.
The surprise is the reactive model's own cost shape.
A query fanning out to many subscribers re-runs on every write to any document it read.
A poorly scoped query over a hot table can multiply your function-call bill.
Manageable with narrow scoping, pagination and avoiding giant subscribed collections, but a discipline to learn.
Neither is expensive at small scale.
Both beat a two-week detour building what they give you.
Model your own numbers from the category table, not either landing page.

Auth, storage and the rest of the platform

Supabase auth is the more complete product.
Email/password, magic links, many OAuth providers, phone OTP, MFA.
Critically, it issues a JWT that Postgres itself reads for row-level security.
Elegant, but RLS is easy to get subtly wrong, and wrong means a data leak.
Test policies deliberately.
Convex leans on external identity: first-class Clerk and Auth0, plus its own auth library.
Authorisation lives in your functions as ordinary TypeScript.
Easier to reason about and test than policy DSLs.
The cost: remembering the check in every function is your job.
Both include file storage with signed URLs, vector search and full-text search.
Full-text search is fine in-app, not a Meilisearch or Typesense replacement.
Supabase's dashboard is the better data browser.
Convex's dashboard is the better function-observability tool, with live logs and history.
For a third option, the hub covers InstantDB, Triplit, ElectricSQL, PocketBase and Appwrite.

Frequently asked questions

Is Convex just Firebase with types?

No. Firebase uses document-level listeners with no transactional joins.
Convex runs your query as a serialisable transaction, re-running when anything it read changes.
Convex also gives real ACID mutations across documents, which Firestore never has.

Can I use Convex and Supabase together?

Yes, some teams do: Supabase Postgres for reporting and analytics, Convex for the live surface.
It's more moving parts and a sync problem you now own.
Only do it with a concrete reason; most teams should pick one.

Which is better for AI agents?

Convex, in most cases.
Agents produce long-running jobs with state a UI must watch.
Convex's scheduled functions plus automatic subscriptions cover that without extra infrastructure.
Supabase can do it, but you'll add a queue, a worker and status streaming.

Does Supabase lock me in at all?

Less than most, but not zero.
The database is plain Postgres and moves cleanly.
Auth, Storage, Edge Functions and RLS style are the sticky parts.
Re-homing auth users is fiddliest: password hashes and provider identities.

What about cost at scale?

Supabase becomes a familiar, predictable compute-sizing exercise.
Convex becomes a query-shape exercise: costs scale with function calls and bandwidth.
A broadly scoped subscribed query over a hot table is what bites.
Both are cheap below serious traffic.

Which has the better local development story?

Supabase, narrowly: the CLI runs the whole stack in Docker with migrations in your repo.
That suits teams wanting deterministic CI.
Convex's dev deployment plus live push is a faster inner loop, but it's cloud, not local.

All convex alternatives, compared field by field

Firebase vs SupabaseShould I use Firebase or Supabase for a new app?