Direct answer
The best free database for side projects in 2026 is Supabase: 500 MB of managed PostgreSQL with built-in auth, real-time, and a REST/GraphQL API — free forever, no credit card. Choose Neon if you prefer a pure serverless Postgres that sleeps to $0 and auto-scales.
Why Supabase wins for side projects
Supabase gives you a production-grade Postgres rather than a toy database. The Free plan includes:
- 500 MB database storage
- 2 free projects (projects pause after 1 week of inactivity; resume in ~1s)
- 50,000 monthly active users for auth
- 5 GB egress + 5 GB cached egress per month
- 1 GB file storage
- Real-time subscriptions and an auto-generated API
| Feature | Supabase Free |
|---|---|
| Database | PostgreSQL (managed, Supabase-owned) |
| Storage | 500 MB |
| Projects | 2 (pause after 1 week idle) |
| Egress | 5 GB/month |
| Auth MAU | 50,000/month |
| Backups | Not included (Pro has daily backups) |
| Expiry | None — free forever |
Best alternatives (verified 2026-09-27)
| Provider | Type | Free tier | Expiry |
|---|---|---|---|
| Supabase | Managed Postgres | 500 MB, 2 projects | Never |
| Neon | Serverless Postgres | 0.5 GB/project, 100 CU-hrs/project | Never |
| Render | Postgres | 1 GB, 1 instance | 30 days |
| AWS DynamoDB | NoSQL | 25 GB, 25 RCU/WCU | Never |
| Firestore | NoSQL | 1 GiB, 50K reads/day | Never |
| Azure Cosmos DB | NoSQL | 1,000 RU/s + 25 GB | Never |
Picking the right one
- Full-stack app with auth: Supabase (database + auth + storage in one).
- Sleep-to-zero serverless: Neon — 100 compute-hours per project, scales to zero after 5 min idle.
- Long-lived free Postgres: both Supabase and Neon are permanent; avoid Render for permanent data (30-day expiry).
- NoSQL / high throughput: DynamoDB’s 25 GB always-free is the most generous.
- Existing Firebase stack: Firestore’s free tier (50K reads/day) works well if you’re already in the Firebase ecosystem.
Numbers verified against official vendor pages on 2026-09-27. Free tiers change — always check the live comparison tables for updates.