Supabase

Supabase is an open-source backend built on Postgres. You get a real Postgres database with authentication, row-level security, auto-generated APIs, realtime subscriptions, file storage, and edge functions layered on top — without giving up SQL or the ability to take the database elsewhere.

It runs behind most of what we build, including this site. The reason is unglamorous: it's Postgres. Row-level security means authorisation rules live next to the data instead of being reimplemented in every client, and when a project outgrows the hosted product, the escape hatch is a standard Postgres dump rather than a migration project.

Firebase is the obvious comparison and the trade is document store versus relational: Firebase is faster to start and harder to query well once relationships matter. Neon and PlanetScale are the picks if you want managed Postgres or MySQL without the surrounding auth and storage layer. Appwrite is the closest open-source alternative in scope. Our rule of thumb is simple — if the data has relationships, start relational, because retrofitting them later is the expensive version.