Supabase vs Firebase: Backend-as-a-Service Comparison

Firebase is Google's proprietary Backend-as-a-Service, using NoSQL (Firestore) and a real-time sync model. It's deeply integrated with the Google Cloud ecosystem and excels at mobile apps with real-time requirements. Supabase is open-source and uses PostgreSQL — a proper relational database. It offers row-level security (RLS), full SQL queries, and a PostgREST API layer. Firebase is older, more mature, and has a larger ecosystem. Supabase is the developer-friendly, SQL-native, open-source alternative with better data portability.

Supabase's free tier is generous — 2 projects, 500MB database, 1GB file storage, 50K monthly active users for auth, and 2GB bandwidth. The free tier pauses projects after 1 week of inactivity (can be reactivated). The Pro plan is $25/project/month and removes pausing. Firebase's free tier (Spark plan) allows 1GB Firestore storage, 10GB/month bandwidth, 50K reads/day, and 1GB hosting storage. For most hobby projects, both free tiers are sufficient. Supabase Pro at $25/project is often cheaper than Firebase at scale due to Firebase's per-read/write pricing.

Yes — Supabase is fully open-source (Apache 2.0) and can be self-hosted using Docker Compose. The self-hosted stack includes PostgreSQL, PostgREST, GoTrue (auth), Realtime, and Kong (API gateway). This is a significant advantage over Firebase, which is Google-hosted only with no self-host option. Self-hosting Supabase is popular for GDPR compliance, air-gapped environments, and cost optimization at high scale. The official self-host docs walk through setup on any VPS or Kubernetes cluster.

Firebase Realtime Database and Firestore were built ground-up for real-time sync — they're battle-tested for high-throughput real-time use cases like chat apps, collaborative editors, and live dashboards. Supabase also supports real-time subscriptions via PostgreSQL's logical replication (listen/notify). Supabase Realtime has improved significantly and handles most real-time use cases well. For extreme real-time scale (millions of concurrent connections), Firebase's infrastructure is more proven. For typical SaaS apps, collaborative tools, and dashboards, Supabase Realtime is more than sufficient and has the advantage of SQL queries.