Free tier databases look generous until you hit the limit that matters: storage, connections, or the row count that forces a paid plan at the worst moment. Neon, Supabase and Railway all offer free tiers, but they cap different things, and the trap is choosing by the headline number instead of by your actual workload. This guide compares the limits that matter and the migration traps to avoid.

The Limits That Actually Matter

Storage is the obvious limit, but connection count is the one that breaks applications: a free tier that allows five simultaneous connections will fail under real traffic, even with plenty of storage left. Row counts, compute hours, and backup retention also matter, and each provider caps a different combination. Check all four limits before you choose, and test with realistic traffic, not with a single user.

Neon: Serverless Postgres

Neon offers serverless Postgres with a free tier that includes generous storage and compute hours, plus branching, which lets you create a copy of your database for testing in seconds. Its autoscaling suits applications with variable traffic, and its free tier is genuinely usable for small projects. The limit to watch is compute hours: idle databases scale to zero, which saves money but adds a cold-start delay on the first query.

Supabase: The Full Backend

Supabase is more than a database: it adds authentication, storage, and realtime features on top of Postgres, which makes it the best choice when you need a whole backend rather than just a database. Its free tier includes a 500MB database and generous API calls, which is enough for small applications. The limit to watch is the database size and the number of API requests, both of which grow faster than you expect once real users arrive.

Railway: The Simple Deploy

Railway's free tier includes a Postgres database that deploys alongside your application with one click, which makes it the simplest option for a small project. The limits are tighter than Neon's or Supabase's, and the free tier is designed for development rather than production. Choose Railway when you want the database and the app in one place with minimal setup, and plan to migrate when traffic grows.

Migration Traps to Avoid

The biggest trap is proprietary features: if your application depends on a provider-specific extension or service, migrating becomes painful. Stick to standard Postgres features and keep your data exportable, so you can move to any provider. Test the migration path before you need it: export your data, import it elsewhere, and confirm the application works. A free tier is a starting point, not a marriage, and the exit should be easy.

Planning Your Exit Before You Enter

The best time to plan a database migration is before you choose the database: check the export format, the migration tools, and the cost of moving your data out. A database that exports cleanly to a standard format is a safe choice, even if its features are weaker, because the exit is what protects you. The worst choice is a database that locks you in with a proprietary format and no export tool. Plan the exit, then choose the database, and you will never be trapped by a free tier that stops being free.

Key Takeaways

- Connection count breaks apps before storage does - Neon offers serverless Postgres with branching; Supabase adds auth and storage - Railway is simplest for a database alongside your app - Stick to standard Postgres so migration stays easy

Frequently Asked Questions

What is the best free tier database? Neon for serverless Postgres with branching, Supabase for a full backend with auth, and Railway for the simplest deploy. Choose by your workload, not the headline number.

A free database is a starting point, not a marriage. Check all four limits, test with real traffic, and keep the exit easy.