PHP CS Fixer vs PHPStan
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A PHP tool that automatically fixes code to follow coding standards.
Open source · MIT
A PHP static analysis tool that finds bugs in code without running it.
The short answer
Choose PHP CS Fixer if you need…
- PHP teams that want consistent code style without manual review comments
- Developers working on large PHP projects where hand-fixing style is tedious
- Projects that want to follow the PER-CS or Symfony coding standards
- Teams planning to migrate older PHP or PHPUnit code to newer syntax
Choose PHPStan if you need…
- PHP developers who want to catch bugs earlier than tests alone allow
- Teams maintaining large PHP codebases
- Developers who want stricter checks on existing PHP code
Side-by-side
| PHP CS Fixer | PHPStan | |
|---|---|---|
| Type | Dev tool | Dev tool |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 13.6k | 14.1k |
| Setup difficulty | Beginner | Intermediate |
| How you get it | Install with a package manager | See the README |
| Main language | PHP | PHP |
| Last code update | 5 days ago | 4 days ago |
What each one is
PHP CS Fixer
PHP CS Fixer is a command-line tool that detects and automatically fixes style problems in PHP code so it follows a chosen coding standard. It ships with built-in rule sets such as PER-CS, Symfony and its own opinionated set, and teams can define their own style in a configuration file. It can also help modernise code toward newer PHP and PHPUnit versions.
PHPStan
PHPStan is a tool that checks PHP code for errors without executing it. It reads your code and reports likely bugs, such as calls that will fail, before you run the code or write tests for it. The README says it aims to make PHP's correctness checkable line by line before running, similar in spirit to compiled languages.
Best for
PHP CS Fixer
- PHP teams that want consistent code style without manual review comments
- Developers working on large PHP projects where hand-fixing style is tedious
- Projects that want to follow the PER-CS or Symfony coding standards
- Teams planning to migrate older PHP or PHPUnit code to newer syntax
PHPStan
- PHP developers who want to catch bugs earlier than tests alone allow
- Teams maintaining large PHP codebases
- Developers who want stricter checks on existing PHP code
Strengths
PHP CS Fixer
- Automatically fixes issues rather than only reporting them
- Offers several established built-in rule sets to choose from
- Supports custom rules and team-specific configuration files
PHPStan
- Finds whole classes of bugs without needing to run the code
- Open source under the MIT license with an active project history
- Official documentation, config reference, and an online playground are available
Not ideal for
PHP CS Fixer
- Projects not written in PHP, since the tool only targets PHP code
- Users on PHP versions outside the supported range (7.4 to 8.5) unless they accept the README's 'at your own risk' option
- Anyone who wants a tool that changes code behavior checks only; some migration rules are marked risky and should be reviewed
PHPStan
- Non-PHP developers, since it only analyzes PHP code
- People looking for a runtime testing framework; PHPStan does not run your code, so it complements tests rather than replacing them
- Those who need a graphical interface without paying, since the web UI is part of the paid PHPStan Pro add-on
Trade-offs
PHP CS Fixer
- Support for the newest PHP versions can lag behind their release, as the README notes
- Some migration rule sets are marked risky and need careful review before use
- Editor support is native only for PhpStorm; other editors rely on community plugins
PHPStan
- The README does not detail setup steps, so you must follow the linked documentation to get started
- Its most convenient interface (web UI and watch mode) is a paid add-on, PHPStan Pro
- Static analysis can only judge what it can infer from the code, so results depend on the code's type information
Getting started
PHP CS Fixer
Install with Composer (recommended)
composer require --dev friendsofphp/php-cs-fixerInstall alternative package if dependency conflicts occur
composer require --dev php-cs-fixer/shimPHPStan
Clone the repository
git clone https://github.com/phpstan/phpstanFrequently asked questions
What is the difference between PHP CS Fixer and PHPStan?
PHP CS Fixer: A PHP tool that automatically fixes code to follow coding standards. PHPStan: A PHP static analysis tool that finds bugs in code without running it. PHP CS Fixer suits php teams that want consistent code style without manual review comments, while PHPStan suits php developers who want to catch bugs earlier than tests alone allow.
Are PHP CS Fixer and PHPStan free?
PHP CS Fixer: Free and open source. PHPStan: Free and open source.
Which is easier to set up, PHP CS Fixer or PHPStan?
PHP CS Fixer is easier to get started with (rated beginner); PHPStan is rated intermediate and usually needs more setup.
Is PHP CS Fixer or PHPStan more popular?
PHPStan has more GitHub stars (14.1k) than PHP CS Fixer (13.6k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to PHP CS Fixer and PHPStan?
Other options people compare them with include Infer.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.