Cloud SQL vs Firestore

Firestore fits document-oriented data, app-friendly sync patterns, and denormalized reads. Cloud SQL fits relational data, transactions, reporting, admin workflows, and queries that combine multiple entities.

Firestore can start with very low fixed cost, but read-heavy screens need careful design. Cloud SQL usually has fixed monthly cost even with low traffic, but complex queries and aggregation are easier to reason about.

Many products can use both: Firestore for app-facing realtime or document flows, and Cloud SQL for admin, billing, reporting, or relational workflows. The calculator helps compare when that extra complexity is justified.