Supabase vs Convex (2026): The Definitive Comparison

Supabase and Convex are the two most compelling backend platforms for modern web apps — but they're built on fundamentally different philosophies. Supabase says "use PostgreSQL for everything." Convex says "rethink the backend from scratch."

The Core Difference

Supabase wraps PostgreSQL with managed services (auth, storage, real-time, edge functions). You get the full power of SQL with convenience layers on top.

Convex is a purpose-built reactive backend. Your database, server functions, and real-time sync are one unified system where everything is automatically reactive.

This philosophical difference affects everything.

Quick Comparison

Feature	Supabase	Convex
Database	PostgreSQL (relational)	Custom document DB (reactive)
Query language	SQL	TypeScript (no SQL)
Real-time	Postgres changes → WebSocket	Automatic (everything is reactive)
Server functions	Edge Functions (Deno)	Server functions (TypeScript)
Schema	SQL migrations	TypeScript schema + auto-migrations
ACID transactions	Full PostgreSQL ACID	Full ACID
Self-hosting	Yes (complex)	No
Open source	Yes (Apache 2.0)	Partially
Free tier	500MB DB, 1GB storage	1GB storage, 256MB DB
Pricing	From $25/mo	From $25/mo

Real-Time: The Biggest Difference

Supabase Real-Time

Supabase real-time listens to PostgreSQL's WAL (write-ahead log) and broadcasts changes via WebSocket.

// Subscribe to changes
const channel = supabase.channel('tasks')
  .on('postgres_changes', 
    { event: '*', schema: 'public', table: 'tasks' },
    (payload) => {
      console.log('Change:', payload)
    }
  )
  .subscribe()

Limitations:

• You subscribe to table-level changes, not query results
• Complex queries (joins, aggregations) can't be subscribed to directly
• Client receives raw change events — you manage local state yourself
• RLS policies apply, but filtering happens after broadcast

Convex Real-Time

In Convex, every query is automatically reactive. Change the data, and every client viewing that data updates instantly.

// This query is automatically real-time
export const getTasks = query({
  args: { projectId: v.id("projects") },
  handler: async (ctx, args) => {
    return await ctx.db
      .query("tasks")
      .withIndex("by_project", q => q.eq("projectId", args.projectId))
      .filter(q => q.eq(q.field("status"), "active"))
      .collect();
  },
});

// Client — automatically re-renders when data changes
const tasks = useQuery(api.tasks.getTasks, { projectId });

Advantages:

• No subscription management — queries are reactive by default
• Complex queries (filters, joins via multiple queries) are all reactive
• Consistency guaranteed — no stale data
• Simpler mental model — "query the data, it stays up to date"

Winner: Convex. Real-time in Convex is effortless. In Supabase, it's possible but requires more manual wiring.

Database Model

Supabase (PostgreSQL)

Full relational database with decades of ecosystem:

• SQL joins across tables
• Extensions (pgvector, PostGIS, pg_cron, etc.)
• Views, materialized views, stored procedures
• Row-Level Security for access control
• Migrations via SQL files

Strengths: Any query PostgreSQL can run, Supabase can run. Complex reporting, aggregations, window functions — all available.

Convex (Document DB)

Purpose-built reactive document database:

• TypeScript schema definitions
• Automatic indexing
• Document relationships via ID references
• No SQL — all queries in TypeScript
• Automatic schema migrations

Strengths: Type-safe queries, no ORM needed, automatic reactivity, simpler mental model for CRUD apps.

Trade-off: Convex can't do SQL joins natively. You query multiple tables and combine in your server function. For simple apps this is fine; for analytics-heavy apps, it's a limitation.

Winner: Supabase for complex queries and the PostgreSQL ecosystem. Convex for type safety and developer experience.

Server Functions

Supabase Edge Functions

Deno-based serverless functions deployed to the edge:

Deno.serve(async (req) => {
  const { userId } = await req.json()
  const { data } = await supabaseClient.from('users').select().eq('id', userId)
  return new Response(JSON.stringify(data))
})

• Separate from database (connect via client library)
• Cold starts possible
• Independent scaling
• Any Deno-compatible code

Convex Functions

TypeScript functions that run in the same system as the database:

export const createTask = mutation({
  args: { text: v.string(), projectId: v.id("projects") },
  handler: async (ctx, args) => {
    await ctx.db.insert("tasks", {
      text: args.text,
      projectId: args.projectId,
      status: "active",
    });
  },
});

• Same runtime as database (no network hop)
• No cold starts
• Automatic retry and error handling
• Built-in scheduling and cron

Winner: Convex for most use cases (tighter integration, no cold starts). Supabase Edge Functions for edge computing or non-database workloads.

Authentication

Supabase Auth is comprehensive: email/password, magic links, OAuth (30+ providers), phone auth, SSO (SAML), anonymous auth. Deeply integrated with RLS policies.

Convex Auth is newer but functional: email/password, OAuth providers, custom auth. Integrates with Clerk and Auth0 for more advanced needs.

Winner: Supabase for breadth and maturity.

When to Choose Supabase

• You need SQL. Complex queries, joins, aggregations, window functions.
• PostgreSQL extensions. pgvector for AI, PostGIS for geospatial, etc.
• Self-hosting matters. Supabase is open-source and self-hostable.
• You already know PostgreSQL. Leverage existing SQL knowledge.
• Analytics/reporting. Connect BI tools directly to your PostgreSQL database.
• Large ecosystem. More SDKs, integrations, and community resources.

When to Choose Convex

• Real-time is core. Collaborative apps, live dashboards, chat, multiplayer.
• Type safety end-to-end. TypeScript from schema to queries to client hooks.
• Developer speed. Less boilerplate, no migrations to manage, no ORM to configure.
• Simple data model. CRUD apps where document model fits naturally.
• You don't want to manage infrastructure. Convex handles everything.

The Hybrid Approach

Some teams use both:

• Convex for the real-time, user-facing application layer
• Supabase/PostgreSQL for analytics, reporting, and data warehousing

Sync data from Convex to PostgreSQL for SQL-based analysis while keeping the real-time app experience on Convex.

FAQ

Can Convex handle complex queries?

Yes, but differently. Instead of SQL joins, you write TypeScript functions that query multiple tables and combine results. For read-heavy analytics, PostgreSQL (Supabase) is more powerful.

Is Supabase real-time good enough?

For many apps, yes. If you need table-level change notifications (new row added, row updated), Supabase real-time works well. If you need reactive complex queries, Convex is significantly better.

Which is cheaper?

Similar at small scale (both have $25/mo Pro plans). At larger scale, Convex's pricing is based on function execution and storage; Supabase's is based on database size and bandwidth. Compare based on your specific usage pattern.

Can I migrate between them?

Possible but non-trivial. Different database models (relational vs document), different query languages (SQL vs TypeScript), and different real-time architectures. Plan for a significant rewrite.

The Verdict

• Supabase if you want PostgreSQL's power, need self-hosting, or have complex query requirements. The safe, proven choice.
• Convex if real-time reactivity is core to your app and you value developer experience over raw SQL power. The modern, opinionated choice.

Both are excellent. The question is whether your app is more "database with real-time features" (Supabase) or "real-time system with a database" (Convex).