Redis vs PlanetScale for Solo Developers

Quick Comparison

Redis Overview

Redis is the in-memory data store that sits behind practically every fast web application. Caching database queries, storing sessions, managing rate limits, running job queues, and enabling real-time pub/sub. All at sub-millisecond speeds. It's not a primary database. It's the tool that makes your primary database's job easier.

I've used Redis in every serious project I've shipped. The pattern is always the same: your app starts getting traffic, database queries become the bottleneck, and adding a Redis cache layer drops response times from hundreds of milliseconds to under one. The data structures (sorted sets, streams, hashes, lists) solve specific problems elegantly without forcing you into workarounds.

Redis Cloud offers a free tier with 30MB, which handles sessions and basic caching for small applications. Self-hosting Redis on a VPS costs nothing beyond your existing server. Either way, Redis is one of the cheapest performance improvements you can make.

PlanetScale Overview

PlanetScale is a serverless MySQL platform built on Vitess, the same technology that powers YouTube's database infrastructure. The headline feature is database branching: create a branch of your production database, test schema changes, and merge them back with zero downtime. No more sweating over migration scripts during deployment.

The developer experience is polished. A web dashboard for managing schemas, a CLI for branching and deployment, and a connection model that works seamlessly with serverless functions. The non-blocking schema change system means your production database never locks up during a migration, which eliminates one of MySQL's biggest pain points.

PlanetScale removed their free tier in 2024, so the entry point is now $39/month on the Scaler plan. That's a tough sell for solo developers working on side projects. For a funded startup or a revenue-generating product, $39/month for worry-free MySQL is reasonable. For weekend experiments, it prices out most indie developers.

Key Differences

Fundamentally different tools. PlanetScale is a primary database for persistent relational data. Redis is an in-memory data store for caching, sessions, and real-time features. They don't replace each other. A well-architected application might use both: PlanetScale for permanent data, Redis for the fast layer.

Data persistence. PlanetScale stores your data durably on disk with replication and backups. Your user data, orders, and content are safe. Redis stores data in memory with optional persistence. Redis data is ephemeral by design. Lose the Redis instance, regenerate the cache from your primary database. Lose PlanetScale data, and you have a real problem.

Query model. PlanetScale gives you full MySQL querying. Joins, subqueries, aggregations, window functions, and indexes. Redis uses key-based lookups with specialized data structure operations. If you need to run complex analytical queries across your data, PlanetScale handles it. Redis is for fast lookups of specific keys.

Schema management. PlanetScale's branching model for schema changes is genuinely innovative. Branch your database, make changes, open a deploy request (like a pull request for your schema), and merge with zero downtime. Redis has no schema. You store whatever data structures you want without declaring anything upfront.

Cost for solo developers. Redis is free to self-host and cheap on cloud providers. PlanetScale starts at $39/month with no free tier. For solo developers watching every dollar, Redis is significantly more accessible. The cost difference alone makes PlanetScale hard to recommend for side projects.

Ecosystem fit. PlanetScale is MySQL-only. If your ORM expects PostgreSQL, PlanetScale won't work. Redis works with any tech stack because it's a supplementary data store, not a primary database.

When to Choose Redis

• You have a primary database and need caching for better performance
• Session management, rate limiting, or job queues are requirements
• You want real-time pub/sub messaging between services
• Budget is tight and you need free or near-free tools
• Your application needs sub-millisecond data access for specific use cases

When to Choose PlanetScale

• You need a managed MySQL database with zero-downtime migrations
• Database branching for testing schema changes safely is important
• Your application is built around MySQL and needs Vitess-scale reliability
• You have revenue to justify the $39/month minimum cost
• Non-blocking schema changes are critical for your deployment workflow

The Verdict

These tools serve different roles, and comparing them directly misses the point.

PlanetScale is a primary database for storing your application's persistent data. Redis is a utility layer for caching, sessions, and real-time features. Most applications that use PlanetScale would also benefit from Redis. They're complementary.

But if I'm advising a solo developer on which to invest in first: Redis wins on value. It's free to self-host, cheap in the cloud, and improves the performance of any application with a primary database. PlanetScale's $39/month entry point with no free tier makes it a hard recommendation for solo developers, especially when Neon and Supabase offer PostgreSQL with generous free tiers.

If you specifically need MySQL (maybe you're running a Laravel or WordPress-adjacent application), PlanetScale's branching and zero-downtime migrations are worth the cost. But for most solo developers, I'd recommend Neon or Supabase for your primary database and Redis for your caching layer. That combination costs less and gives you more flexibility than PlanetScale alone.