PlanetScale vs Supabase

PlanetScale and Supabase are two of the most popular managed database platforms for modern applications, but they target different needs. PlanetScale brings Vitess-powered horizontal MySQL scaling. Supabase provides a full backend platform on PostgreSQL.

Architecture Differences

PlanetScale's Vitess Foundation

PlanetScale is built on Vitess, the sharding middleware that powers YouTube's MySQL infrastructure. It transparently shards your database across multiple nodes while presenting a single MySQL interface. The standout feature is database branching — you can create a branch of your schema, test changes, and merge them through a deploy request, similar to a Git pull request.

Supabase's Full-Stack Approach

Supabase wraps PostgreSQL with a suite of services: auto-generated REST and GraphQL APIs, real-time subscriptions, authentication, file storage, and edge functions. It aims to be a complete backend that replaces Firebase while keeping the power of PostgreSQL underneath.

Schema Migration Workflows

PlanetScale's branching model is a significant differentiator. Deploy requests run schema changes online with no downtime and no locks, using Vitess's built-in online DDL. Supabase uses standard migration files, which work well but lack the branching and preview capabilities.

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Scaling Characteristics

PlanetScale can scale writes horizontally through Vitess sharding, making it suitable for applications that outgrow a single MySQL instance. Supabase scales vertically (bigger instances) and adds read replicas for read-heavy workloads, but write scaling is limited to a single primary.

Choosing Between Them

The choice often comes down to whether you need a scalable database (PlanetScale) or a full backend platform (Supabase). Review pricing for both as their cost models differ significantly at scale.

The Bottom Line

Choose PlanetScale when you need horizontally scalable MySQL with safe schema migrations. Choose Supabase when you want a full backend platform with auth, real-time, and the PostgreSQL ecosystem.