All comparisons
Comparison
PostgresvsMySQL
TL;DR
Postgres wins on features, extensions, JSON support, and developer experience. MySQL wins on horizontal scale-out via Vitess and on operational simplicity at very large traffic. For new projects in 2026, Postgres is the default.
New SaaS project
Postgres
Massive write-heavy scale
MySQL (Vitess)
JSON + relational hybrid
Postgres
AI-paired development
Postgres
| Feature | Postgres | MySQL |
|---|---|---|
| JSON support | jsonb with indexing | JSON type (slower indexing) |
| Window functions / CTEs | First-class | Available, slightly clunkier |
| Extensions | Huge ecosystem (pgvector, PostGIS…) | Plugin model, fewer modern picks |
| Replication | Streaming + logical | Statement / binlog / GTID |
| Horizontal scaling | Citus, partitioning | Vitess (mature) |
| Default isolation | Read committed | Repeatable read |
| Type system | Strict, custom types possible | More permissive coercions |
| Vendor ecosystem (2026) | Supabase, Neon, Crunchy, RDS | PlanetScale, RDS, MariaDB |
| AI-agent friendliness | High (clean introspection) | High (similar story) |
When Postgres wins
- Your domain mixes relational and document data.
jsonbis the killer feature MySQL hasn't matched. - You write analytical queries against operational data. Postgres's window functions, CTEs, and planner pull ahead.
- You want pgvector for RAG without standing up a second system.
- You're building on Supabase, Neon, or any of the modern Postgres-first platforms.
When MySQL wins
- You're past the scale where a single-writer Postgres fits, and Vitess's sharding story is simpler than Citus for your team.
- You're already on AWS Aurora MySQL and the operational team is fluent.
- Your team genuinely prefers MySQL's quirks (silent type coercion, the way GROUP BY works before strict mode).
Honest take
Postgres has been the default for new projects since roughly 2020. The 2026 question isn't whether Postgres "won" (it did, for most purposes); it's whether MySQL's operational advantages at extreme scale still matter for your project. For 95% of new SaaS, the answer is no, and Postgres is the calmer choice. For the 5% that genuinely need Vitess-scale sharding, MySQL still ships.