PostgreSQL vs MySQL for Modern Web Apps in 2026
PostgreSQL vs MySQL compared on data types, query power, transactions, cloud options, and real production experience. Which database should you choose in 2026?
PostgreSQL and MySQL are both proven, production-grade databases used by millions of applications. But the choice matters more than most developers think — not because one is broken, but because they make fundamentally different trade-offs that compound over time as your schema evolves. Here is what six years of running both in production taught me about scaling, migrations, and database choices.
PostgreSQL 16
- ✦ Object-relational database — supports rich data types
- ✦ JSON, JSONB, arrays, ranges, enums, composite types
- ✦ Full ACID compliance, even in complex transactions
- ✦ Advanced query planner with CTEs, lateral joins, window functions
- ✦ Backed by PostgreSQL Global Development Group (independent)
MySQL 8.4 (LTS)
- ✦ Pure relational model, straightforward and predictable
- ✦ Massive hosting support — every shared host offers it
- ✦ InnoDB storage engine: ACID-compliant, row-level locking
- ✦ Excellent replication story (group replication, Galera)
- ✦ Oracle-backed with enterprise support options
Data types: where PostgreSQL runs away
MySQL handles the standard SQL types well: integers, varchars, datetimes, decimals. For 80% of CRUD apps, that is sufficient. The problems emerge when your data doesn't fit neatly into those boxes.
PostgreSQL ships with over 50 built-in data types. The ones that matter most in modern web apps:
JSONB
Binary JSON storage with full indexing. Query inside the JSON, index specific paths, use containment operators. MySQL's JSON type is comparable but slower to query and cannot be indexed at the path level in most cases.
ARRAY
Native array columns. Store a list of tags, user IDs, or permissions directly in a column without a junction table. MySQL has no array type — you serialize to JSON or create a separate table.
UUID
PostgreSQL stores UUID as 16 bytes natively and indexes it efficiently. MySQL stores UUIDs as 36-character strings by default, which are significantly slower to index on large tables.
Storage engine decisions define how your tables are stored and indexed under the hood.
Query power: complex analytics and reporting
MySQL handles standard CRUD queries efficiently. Its query optimiser is solid for simple joins and point lookups. But the moment you need anything beyond basic SELECT-JOIN-WHERE, PostgreSQL's query planner and feature set pull ahead significantly.
-- PostgreSQL: Rank users by revenue in rolling 30-day windows
SELECT
user_id,
SUM(amount) OVER (
PARTITION BY user_id
ORDER BY created_at
RANGE BETWEEN INTERVAL '30 days' PRECEDING AND CURRENT ROW
) AS rolling_revenue,
RANK() OVER (ORDER BY amount DESC) AS revenue_rank
FROM orders;Window functions, CTEs, lateral joins, recursive queries, and partial indexes are all first-class in PostgreSQL. MySQL 8 added window functions and CTEs, but the implementation has edge cases and performance gaps, particularly around correlated subqueries and large result sets.
Transactions and concurrency
Both databases support ACID transactions with InnoDB (MySQL) and the PostgreSQL storage engine. The difference is in the details:
| Feature | PostgreSQL | MySQL |
|---|---|---|
| Isolation levels | All 4 ANSI levels | All 4 ANSI levels |
| Default isolation | Read Committed | Repeatable Read |
| DDL in transactions | Yes — rollback DDL changes | No — DDL auto-commits |
The DDL-in-transactions point is underrated. In PostgreSQL, you can wrap schema changes (like adding columns or creating indexes) in a transaction and roll them back if they fail. This makes migrations dramatically safer. In MySQL, DDL statements auto-commit and cannot be rolled back.
Safer migration strategies keep services online during schema updates.
Where MySQL genuinely wins
PostgreSQL is the better choice for complex data models. But MySQL has real-world deployment advantages:
Ecosystem and host compatibility
MySQL is supported by every shared hosting provider out of the box. Platforms like WordPress and Magento require MySQL-compatible databases and do not support PostgreSQL natively.
Replication and read scaling
MySQL's replication models (Group Replication, Galera) are battle-tested and simple to configure. While PostgreSQL replication is solid, multi-primary replication is complex to set up and maintain.
Summary of managed cloud options
| Provider | PostgreSQL | MySQL |
|---|---|---|
| AWS RDS | ✅ RDS + Aurora PG | ✅ RDS + Aurora MySQL |
| Supabase / Neon | ✅ Supported natively | ❌ Not supported |
| PlanetScale | ❌ Not supported | ✅ MySQL-compatible (Vitess) |
The verdict
If you are starting a new project and are not constrained by hosting, PostgreSQL is the better default choice. The richer type system, transactional DDL, and powerful query planner pay dividends as your database grows. The managed hosting options (Supabase, Neon, RDS) make hosting PostgreSQL just as easy as hosting MySQL.
