Convex vs PlanetScale: Reactive Backend vs Managed Database

Convex and PlanetScale are not direct competitors: one is a complete backend platform and the other is a specialised database service. Convex provides a reactive database, TypeScript serverless functions, file storage, and scheduling in a single product. PlanetScale provides a managed database service with MySQL via Vitess and a newer PostgreSQL offering, and expects you to supply compute, auth, storage, and any other backend services yourself.

The comparison matters because developers choosing a backend for a new TypeScript application often evaluate both. Convex's all-in-one model eliminates the need to assemble separate services. PlanetScale's model delivers a world-class database with features unavailable elsewhere, particularly schema branching and horizontal sharding, but requires more architectural work. The removal of PlanetScale's free tier in April 2024 also changed the calculus significantly: starting a new project now requires budget commitment from the first database. Convex retains a free tier with no inactivity pause, making it the lower-friction starting point for most developers.

Convex is a backend platform rather than a database. It includes a document-relational database where queries are TypeScript functions, serverless function execution for mutations and actions, file storage with a built-in upload and download API, scheduling for cron jobs and delayed functions, real-time query reactivity where clients automatically receive updates when data changes, and a dashboard for monitoring and debugging.

None of these capabilities exist in PlanetScale. PlanetScale is a managed database. Teams building on PlanetScale need to supply a compute platform such as Vercel, Fly.io, or Railway for their application code, a separate auth service such as Clerk or Auth0, an object storage solution such as AWS S3 or Cloudflare R2, and their own implementation of any real-time features. For teams that already have these services in their stack, PlanetScale's focus on the database layer is an advantage. For teams starting from scratch, Convex significantly reduces the number of vendors and integrations required to have a functioning backend.

PlanetScale's schema branching is one of the most operationally significant features of any database platform. Developers create database branches that mirror Git branches, test schema changes in isolation, and merge via deploy requests that apply the change to production using non-blocking DDL. Non-blocking DDL means that an ALTER TABLE statement on a table with billions of rows does not lock writes or cause downtime, a capability that standard MySQL and PostgreSQL do not provide without additional tooling.

This workflow prevents the class of production incident where a schema migration locks a critical table and takes down the application. For engineering teams making frequent schema changes to large datasets, this is a meaningful operational advantage. Convex does not have an equivalent. Convex schema changes are handled in TypeScript and the platform manages backward-compatible migrations, but it lacks the deploy request review workflow and non-blocking DDL guarantees that PlanetScale provides. Teams whose deployment risk profile prioritises database safety over developer convenience will find PlanetScale's approach valuable.

PlanetScale launched managed PostgreSQL in general availability in late 2025, built on a new sharding architecture called Neki, designed from first principles rather than ported from Vitess. Single-node PlanetScale Postgres starts at $5 per month. High-availability Metal instances backed by NVMe storage start at $50 per month. Schema branching and deploy requests are available on the Postgres offering, matching the MySQL platform's workflow.

This expansion changes the comparison: PlanetScale is no longer a MySQL-only platform. Teams that want PostgreSQL with schema branching and professional database operations tooling now have PlanetScale as an option alongside Neon and Supabase. However, PlanetScale Postgres is still newer and has less community history than the MySQL platform. It also does not include auth, storage, or compute, meaning the surrounding stack still needs to be assembled. For teams evaluating Convex vs PlanetScale, the Postgres expansion does not change the fundamental trade-off: Convex is a complete backend, PlanetScale is a database.

PlanetScale removed its free tier in April 2024. As of 2026, MySQL-based PlanetScale plans start at $50 per month for a high-availability cluster. PlanetScale Postgres Single Node starts at $5 per month; PlanetScale Postgres Metal starts at $50 per month. There is no free option for any PlanetScale product. The absence of a free tier means that every new project on PlanetScale requires paid commitment before shipping a single feature.

Convex's free tier includes 1 million function calls per month, 20 GB-hours of compute, basic database storage, and file storage, with no inactivity pause. The Professional plan costs $25 per developer per month and includes 25 million function calls and 250 GB-hours of compute. For a solo developer, Convex is effectively free during development and validation phases. For a four-person team on Convex Professional, the platform costs $100 per month before usage charges. The cost comparison shifts at team scale: a four-person team on Convex Professional plus separate auth and storage services may approach or exceed the cost of PlanetScale plus equivalent services, but Convex's bundled model reduces the total number of vendor integrations.

For developers starting a new TypeScript application who want to ship quickly without assembling a backend stack, Convex is the better default. The free tier, complete platform, and TypeScript-native developer experience reduce time to working software. Real-time reactivity is built in rather than bolted on. The open-source backend (released February 2025) also addresses earlier concerns about vendor dependency.

Choose PlanetScale when your requirements specifically match its strengths: a large MySQL codebase that needs horizontal sharding via Vitess, a team making frequent schema changes to live high-traffic databases who needs deploy request workflows and non-blocking DDL, or a PostgreSQL workload where schema branching is more valuable than an all-in-one backend. PlanetScale's minimum entry price of $5 per month for Postgres Single Node makes it accessible for PostgreSQL-specific use cases, but it remains a database-only product requiring additional services to build a complete application. For most new projects evaluated without existing commitments, Convex's free tier and complete backend model are the more practical starting point.