How do I choose between PostgreSQL and MySQL for a new web app?

For a new web app, both PostgreSQL and MySQL are solid choices. The best one depends on what your app needs more: features and flexibility or simplicity and broad familiarity.

Quick rule of thumb

• Choose PostgreSQL if you want:

  • richer SQL features
  • stronger data integrity
  • advanced querying/analytics
  • JSON support that behaves like a first-class feature
  • room to grow into more complex data models

• Choose MySQL if you want:

  • very common hosting/support
  • simple, straightforward setup
  • a database many teams already know
  • a conventional choice for typical CRUD apps

When PostgreSQL is usually better

PostgreSQL is often the better default for modern web apps because it’s very capable and strict.

Good fit if you need:

• Complex queries and reporting
• Transactions and consistency as a priority
• Advanced data types and indexing
• JSON/JSONB for semi-structured data
• Custom functions, views, CTEs, window functions
• Easier path when your app grows in complexity

Common examples:

• SaaS products
• apps with reporting/analytics
• marketplace platforms
• apps that may evolve beyond basic CRUD

When MySQL is usually better

MySQL is a great fit when the app is straightforward and you value ease and ecosystem familiarity.

Good fit if you need:

• Simple CRUD web app
• lots of existing MySQL experience on the team
• managed hosting that defaults to MySQL
• compatibility with legacy systems or WordPress-style stacks

Common examples:

• content sites
• traditional LAMP-stack apps
• smaller apps with standard relational data

Important differences to consider

1. SQL capabilities

PostgreSQL generally has more advanced SQL features and tends to follow the SQL standard more closely.

2. Data integrity

PostgreSQL is often stricter about correctness, which is a plus if you care about keeping data clean.

3. JSON support

Both support JSON, but PostgreSQL’s JSONB is especially powerful for querying and indexing.

4. Performance

For many common web apps, performance is not the deciding factor. Either can be fast enough. The bigger issue is usually:

• schema design
• indexes
• query quality
• caching
• application architecture

5. Tooling and hosting

Both have excellent tools and managed services. MySQL is slightly more ubiquitous in some shared hosting environments, while PostgreSQL is often preferred in modern cloud setups.

Practical recommendation

If you’re starting a new app and don’t have a strong reason to use MySQL, I’d usually recommend PostgreSQL.

Why:

• more features
• fewer compromises later
• better for evolving product requirements
• strong ecosystem and reliability

Pick MySQL if:

• your team already knows it well
• your deployment environment strongly favors it
• you’re maintaining compatibility with an existing MySQL system

A simple decision checklist

Ask:

1. Will I need complex queries or reporting?
2. Do I expect schema flexibility or JSON-heavy data?
3. Do I care more about strict correctness than convenience?
4. Does my team already have expertise in one of them?
5. Am I integrating with existing infrastructure?

If you answer “yes” to 1–3, lean PostgreSQL.
If 4–5 matter most, choose whichever fits your team and stack.

If you want, I can also give you a decision table for your specific app type or a PostgreSQL vs MySQL comparison by use case.