PostgreSQL and MySQL are the two most widely used open-source relational databases. The choice between them in 2026 is not as balanced as it once was. Here is an honest comparison.
The Current State
PostgreSQL has become the default choice for most new projects in 2024–2026. The reasons: superior JSON support (JSONB is a genuine document store within a relational database), more complete SQL standard compliance, better handling of complex queries, stronger concurrency (MVCC implementation), support for advanced data types (arrays, ranges, composite types, enums), and a more active open-source development community. MySQL remains dominant in two contexts: existing WordPress/LAMP stack deployments (the world has an enormous installed base) and scenarios where MySQL’s read performance under high concurrent reads is specifically needed.
Where PostgreSQL Wins Clearly
JSON/JSONB: PostgreSQL’s JSONB type stores JSON as binary and supports indexing on JSON fields — effectively combining document and relational storage in one database. This eliminates a class of hybrid MongoDB-plus-SQL architectures. Full-text search: PostgreSQL has better native full-text search than MySQL’s, reducing the need for Elasticsearch for simple search requirements. Extensions: PostGIS (geospatial), pgvector (vector embeddings for AI applications), TimescaleDB (time series). If you need geospatial queries or vector similarity search, PostgreSQL is the only practical choice in the relational category.
Where MySQL Remains Relevant
WordPress and the LAMP stack: MySQL is the default for virtually all WordPress deployments and many PHP applications. Changing the database requires migration work with limited benefit for simple content management use cases. PlanetScale (a MySQL-compatible database with GitOps branching features) has made MySQL the choice for teams that want a modern developer experience with MySQL’s existing tooling. Aurora MySQL on AWS remains a popular managed database choice with a large existing user base.
Practical Choice Framework
For a new project in 2026: use PostgreSQL unless you have a specific reason not to (existing MySQL infrastructure, team expertise, specific tool requirements). For WordPress/PHP projects: MySQL is the path of least resistance and perfectly adequate for the workload. For AI/ML applications involving vector search: PostgreSQL with pgvector. For time series data: PostgreSQL with TimescaleDB or a dedicated time series database (InfluxDB, QuestDB). The default answer has shifted — PostgreSQL is the new MySQL for new project choice.
