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Slim

A small PHP framework for building web apps and APIs with routing and PSR-7 support.

GitHub Download 4.15.3
Stars
12.3k
Forks
2k
Licence
MIT
Language
PHP
Last update
5 days ago
Type
Framework

What it is

Slim is a PHP micro-framework for writing web applications and APIs. You define routes that map web addresses to PHP functions, and Slim handles the request and response flow around them. It is designed to stay small, so you add only the parts you need.

  • Create a simple web page or endpoint with a route such as /hello/{name}
  • Build a JSON API by returning responses from route handlers
  • Add error handling middleware with addErrorMiddleware
  • Use the built-in PHP development server to test an app locally

Great for

  • PHP developers who want a lightweight alternative to a full-stack framework
  • Building small JSON or HTTP APIs with a few routes
  • Projects that want to choose their own PSR-7 HTTP message implementation
  • Learning how HTTP routing and middleware work in PHP

Not ideal for

  • Teams wanting a full framework with built-in ORM, admin panels, and batteries included, because Slim leaves many of those choices to you
  • Projects that must run on PHP versions older than 7.4, since the README states PHP 7.4 or newer is required
  • Non-PHP developers, since the project is entirely PHP-based
Step-by-step guide: how to use SlimInstall, first run, examples, tips and FAQs
Slim vs SymfonyCodeIgniter vs Slim

How to get it

  1. 1

    Install with a package manager

    You'll need: PHP 7.4 or newer · Composer

    Install Slim with Composer

    composer require slim/slim
  2. 2

    Run it

    • Install a PSR-7 implementation such as composer require slim/psr7
    • Create public/index.php and add the Hello World routes from the README
    • Run php -S localhost:8000 -t public from the project folder
    • Open http://localhost:8000/hello/world in your browser
  3. 3

    Get the most out of it

    • Install Slim-Http decorators with composer require slim/http for extra request and response helpers
    • Choose a PSR-7 implementation that fits your performance or stream-handling needs, as the README compares several
    • Read the official documentation at slimframework.com for web server configuration
    • Run the test suite with composer test after cloning to explore the code

Downloads

Source code (.zip)4.x branch · straight from GitHubRelease 4.15.3Release notes and sourceOfficial website & docsslimframework.com

Strengths

  • Small and focused, as described as a micro-framework
  • Built on PSR-7, PSR-15, and PSR-3 standards per its topics and README
  • Installs with a single Composer command and works with several PSR-7 libraries

Trade-offs

  • Minimal by design, so you must pick and wire together libraries for things like databases and templating
  • The README points to external documentation for web server setup rather than covering it in depth
  • Choosing a PSR-7 implementation adds an early decision the beginner must understand

How it compares

ProjectStarsTypeLevelUpdatedBest for
Slim (this)12.3kFrameworkintermediate5 days agoPHP developers who want a lightweight alternative to a full-stack framework
symfony31.2kLibraryintermediate4 days agoPHP developers building web applications that need a structured framework
framework35kFrameworkintermediate4 days agoPHP developers building web applications or APIs
guzzle23.4kLibraryintermediate11 days agoPHP developers who need to call external REST or web service APIs
monolog21.4kLibraryintermediate5 days agoPHP developers who need structured logs from an application
pest11.8kLibraryintermediate4 days agoPHP developers who want to add automated tests to a project

Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.