Supabase vs PlanetScale Security: Complete 2026 Comparison

Fundamental Differences

Supabase and PlanetScale represent two fundamentally different approaches to database-as-a-service:

• Supabase is a full Backend-as-a-Service (BaaS) platform built on PostgreSQL. It provides authentication, real-time subscriptions, storage, and auto-generated APIs alongside the database.
• PlanetScale is a serverless MySQL-compatible database built on Vitess (the technology powering YouTube's database). It focuses purely on database functionality without bundled authentication or APIs.

Access Control Models

Supabase Row Level Security (RLS)

Supabase uses PostgreSQL's Row Level Security to enforce access control at the database level. This means even if an attacker gains access to your API credentials, they can only see data that RLS policies permit.

-- Example: Users can only access their own orders
CREATE POLICY "Users can view own orders"
ON orders FOR SELECT
USING (auth.uid() = user_id);

-- Example: Team members can access team data
CREATE POLICY "Team members can view team projects"
ON projects FOR SELECT
USING (
  team_id IN (
    SELECT team_id FROM team_members 
    WHERE user_id = auth.uid()
  )
);

RLS Advantages:

• Security enforced at the lowest level (database)
• Cannot be bypassed by application bugs
• Works with direct database access and API access
• Policies are declarative and auditable

PlanetScale: Application-Level Security

PlanetScale does not provide built-in row-level security. Access control must be implemented in your application code or API layer.

// Example: Node.js API with access control
app.get('/api/orders', async (req, res) => {
  const userId = req.user.id; // From your auth middleware
  
  // Access control in application code
  const orders = await db.query(
    'SELECT * FROM orders WHERE user_id = ?',
    [userId]
  );
  
  res.json(orders);
});

Application-Level Security Trade-offs:

• Full flexibility in access control logic
• Bugs in application code can expose data
• Each endpoint needs security review
• Database credentials must be protected on server

Connection Security

Supabase Connection Options

• REST API (PostgREST) - HTTPS encrypted, uses anon/service role keys
• Realtime (WebSocket) - WSS encrypted, respects RLS
• Direct PostgreSQL Connection - SSL/TLS encrypted, uses connection pooling (Supavisor)
• Edge Functions - Server-side with service role access

PlanetScale Connection Options

• MySQL Protocol - TLS encrypted connections
• PlanetScale Serverless Driver - HTTP-based, works in serverless environments
• Database.js (Edge) - Cloudflare Workers compatible
• Connection Strings - Username/password authentication

Database Branching & Security

Both platforms offer database branching, but with different security implications:

Supabase Branching

Supabase branching creates isolated database environments for development. Each branch has its own:

• Separate API keys (anon and service role)
• Separate authentication state
• Cloned RLS policies
• Isolated data (no production data by default)

PlanetScale Branching

PlanetScale pioneered database branching with their "Deploy Requests" workflow:

• Branches have separate connection credentials
• Schema changes reviewed before merging
• Safe migrations without locking tables
• Optional data seeding (no automatic prod data cloning)

API Exposure Risks

Supabase: Direct Client Access

Supabase's architecture means your database is exposed via public APIs. This is secure when configured correctly, but creates specific risks:

• Anon key exposure - Expected and safe if RLS is configured
• Service role key exposure - Critical vulnerability, bypasses all security
• RLS misconfiguration - Tables may be publicly accessible
• Missing RLS on new tables - Developers forget to add policies

Use our Security Checklist or Leak Scanner to audit your Supabase project.

PlanetScale: No Direct Client Access

Since PlanetScale doesn't expose APIs to clients, the attack surface is different:

• Connection string exposure - Critical vulnerability, full database access
• SQL injection in your API - No database-level protection
• Over-permissioned database users - Application uses single privileged connection
• Audit logging gaps - Need to implement your own

Side-by-Side Security Comparison

Final Verdict

The bottom line: Both can be equally secure. Supabase requires diligent RLS configuration but provides defense in depth. PlanetScale has a simpler security model but requires you to build and secure your own API layer.

Related Resources

• Supabase Security Best Practices Guide
• Anon Key vs Service Key Explained
• 25+ RLS Policy Patterns
• Supabase vs Firebase Security