Hey PHP fans! Welcome to 2025—a year where PHP continues to shine as the backbone of the web (sorry, haters, it’s not going anywhere!). If you’re building a slick API, a lightweight app, or just want to ditch the bloat of full-stack frameworks, micro frameworks are your ticket to coding bliss. Today, we’re diving into the top four PHP micro frameworks: Slim PHP, Flight PHP, Fat-Free Framework (F3), and Lumen—plus a few honorable mentions to keep things spicy.
I’ll break down their popularity (with a special zoom-in on the past year), ease of getting started, and how they scale from "Hello World" to "Holy Complexity, Batman!" I’ll also toss in some fresh code snippets from their latest versions—no outdated stuff here! Oh, and watch for a certain framework that’s been quietly stealing the show lately (hint: it rhymes with "light"). Let’s dive in!
The Top Four: Slim, Flight, Fat-Free, and Lumen
Slim PHP: The Lean, Mean Routing Machine
Slim PHP is like that reliable friend who always shows up on time—minimalist, focused, and ready to handle your HTTP requests with finesse. It’s a micro framework kingpin, loved for its simplicity and flexibility, especially when crafting RESTful APIs. Slim 4 (the latest as of 2025) keeps things lean with no third-party dependencies out of the box, but it’s extensible enough to grow with your project.
- Popularity: Slim’s been a staple for years, boasting a solid GitHub presence with 12.1k stars. In 2024, it held steady traction—not the explosive growth of newer players, but its community is active and reliable for devs who want control without chaos.
- Simplicity: Getting started is a breeze—install via Composer, define some routes, and you’re off. Scaling up? Add middleware or libs like Twig or Eloquent as needed.
- Example (Slim 4):
use Psr\Http\Message\ResponseInterface as Response;
use Psr\Http\Message\ServerRequestInterface as Request;
use Slim\Factory\AppFactory;
require __DIR__ . '/vendor/autoload.php';
$app = AppFactory::create();
$app->get('/hello/{name}', function (Request $request, Response $response, array $args) {
$name = $args['name'];
$response->getBody()->write("Hello, $name!");
return $response;
});
$app->run();
Run that, hit /hello/PHP, and boom—Slim delivers. It’s simple, but for complex apps, you’ll need to bolt on extras yourself and the dependencies only grow from there.
Flight PHP: The Rising Star Ready to Soar
Let’s talk about Flight PHP—the micro framework that’s been flapping its wings and stealing the spotlight in 2025! Flight 3 (the latest version) is fast, extensible, and so beginner-friendly it practically hands you a welcome mat. With zero dependencies and a focus on simplicity and power, it’s the framework you didn’t know you needed until now. It can handle tiny one-off projects or complex projects with many requirements. New features like route groups, middleware, dependency injection handlers, and aliases added in 2024 have sent it rocketing past competitors in popularity. It also helps that the framework is 100% unit tested unlike some other competitors!
- Popularity: Flight’s GitHub stars just eclipsed Fat-Free’s in February 2025 (woo-hoo!), and its 2024 updates fueled a buzz that’s still growing. Devs on X are raving about its speed and fresh features—Flight’s the one to watch this year!
-
Simplicity: Install via composer with
composer require flightphp/core, or download and unzip the repo from, drop a few lines in anindex.phpfile, and you’re coding! It’s perfect for quick prototypes yet scales effortlessly with dependency injection and middleware for bigger builds. - Example (Flight 3):
require 'vendor/autoload.php';
Flight::route('GET /hello/@name', function ($name) {
echo "Hello, $name! Welcome to Flight 3!";
});
Flight::start();
Look at that—no fluff, just results! Flight’s lightweight core (faster than Slim by ~50% in TechEmpower benchmarks) and built-in goodies make it a dream for newbies and pros alike. Ready to take off with your next project? Flight’s calling your name!
Fat-Free Framework (F3): The Minimalist Veteran
Fat-Free Framework, or F3, is the wise old sage of micro frameworks—around since 2009, it’s still kicking with a tiny 90KB footprint (though I fact checked it, and it's actually 412kb of PHP files!!!). It’s all about balance: lightweight yet packed with features like ORM, templating, and caching. F3’s modular design lets you pick and choose what you need, keeping your app lean.
- Popularity: With 2.6k GitHub stars, F3 has a loyal following, though its 2024 growth was steady rather than meteoric. It’s a mature choice with a tight-knit community that’s always tinkering.
- Simplicity: Composer or no Composer required—just unzip and go from fatfreeframework.com. It’s beginner-friendly, but its flexibility shines when you dig into its plugins for complex projects.
- Example (F3 3.9):
require 'vendor/autoload.php';
$f3 = \Base::instance();
$f3->route('GET /hello/@name', function ($f3, $args) {
echo 'Hello, ' . $args['name']. '! F3 keeps it light!';
});
$f3->run();
F3’s fast, clean, and extendable, but its docs assume some PHP know-how. It’s a solid pick for devs who love minimalism with a side of power.
Lumen: The Laravel Lightweight (But Let’s Be Real…)
Lumen sneaks into our top four as Laravel’s little sibling, designed for microservices and APIs. It’s got a minimalist vibe, but here’s the tea: it’s basically Laravel Lite, carrying some of the same heft under the hood. While it’s fast for a Laravel offshoot, its performance lags behind true micro frameworks like Flight or Slim—check the TechEmpower benchmarks for proof.
- Popularity: Lumen’s got 7.6k GitHub stars and a decent following, but its 2024 buzz was quieter than Flight’s meteoric rise. It leans hard on Laravel’s ecosystem, which is great if you’re already in that world, less so if you want something standalone.
- Simplicity: If you know Laravel, it’s a cinch—Composer install, tweak a few configs, and go. For newbies, though, it’s a bit more involved than Flight or F3.
- Example (Lumen 8):
require __DIR__ . '/../vendor/autoload.php';
$app = new Laravel\Lumen\Application(__DIR__ . '/../');
$app->get('/hello/{name}', function ($name) {
return "Hello, $name! Lumen says hi.";
});
$app->run();
It’s fine for quick APIs, but Lumen’s heft makes it less exciting compared to leaner options. Laravel fans might dig it; others might yawn.
Honorable Mentions: Hidden Gems of 2025
- Leaf PHP: A newer kid on the block, Leaf’s simplicity and modern vibe are gaining traction. It is an old fork of Laravel so it has a certain level of familiarity to some. It’s not as battle-tested as the top four, but worth a peek!
- Bullet PHP: Ultra-light and REST-focused, Bullet’s a niche choice for API wizards. It’s less popular but shines in specific use cases.
- Silex: A Symfony-backed micro framework that's sadly deprecated and no longer support. You gave it your all Silex!
The Verdict: Which One Wins in 2025?
- Popularity (Past Year): Flight PHP takes the crown—its 2024 updates and community hype have it soaring past Fat-Free and nipping at Slim’s heels. Slim’s still a heavyweight, Lumen’s coasting on Laravel’s fame, but Flight’s the fresh face everyone’s talking about.
- Simplicity: Flight edges out with its one-file setup and no-dependencies vibe—perfect for newcomers. Slim and F3 are close behind, while Lumen’s Laravel ties make it a bit clunkier.
- Scalability: All four scale well, but Flight’s built-in features (middleware, DI) give it a subtle boost for growing projects without extra legwork or libraries. Slim needs add-ons, F3’s modularity takes planning, and Lumen’s just… Laravel Lite.
If you’re new to PHP or want a fun, fast ride, Flight PHP is your 2025 must-try. It’s simple enough to start in minutes, powerful enough to build something epic, and—let’s be real—its recent glow-up makes it the coolest kid in class. Slim and F3 are fantastic too, while Lumen is… well, fine if you’re already married to Laravel. So, grab Flight 3, code something awesome, and let’s soar into 2025 together!
What’s your favorite micro framework? Drop a comment—I’d love to geek out with you!
Top comments (3)
While I admire that you are maintaining a framework. I got some questions.
I'm wondering why all the frameworks, except Lumen support dead PHP versions.
By restricting themselves to a dead language version they are missing out on language features, but more importantly on security.
I asking myself why micro frameworks want to invent their own router. There is no shame to pick the fastest router package for your framework. I found a benchmark.
One thing where micro frameworks should shine is routing.
While I sometimes want to choose for a micro framework, Symfony makes it too simple to check out other options. And it has the benefit of going to full framework if needed.
The same can be said about Lumen and Laravel.
That is something a micro framework can never provide.
As for Flight, the reason why it maintains PHP 7.4 because that is still the supported version on Rocky/Alma Linux version 8, and will be for a few more years. That was the old CentOS distro that powered a good chunk of the servers around the world along with Ubuntu 20.04 LTS which is still sporting PHP 7.4 for a few more months. We'll drop support for it in v4 of Flight when we get around to that.
As to your other points about Lumen, Symfony and Laravel, you can totally use them and they have better use cases compared to a micro framework. Micro frameworks are routers with some flair (though Flight could handle a very large and complex project). I have made several complex projects with Fat-Free in the past and they held up well, but I feel that Flight fills in some of the gaps that F3 missed. If you know you're planning an enterprise grade software platform, and you have the backing and support to do it, totally go for it! Though I will say that's for the minority, not majority of projects.
It is a bit of a weird update policy for me. I don't think if you want to support an LTS version of an OS, you have to support the PHP version it comes with.
Good operations people update the packages that run on their systems. And even if they do it conservatively they should be on 8.1, planning to move to 8.2.
I am not saying micro frameworks can't handle large projects. Most developers want a structure that gives them more confidence and let them concentrate on the custom requirements of the project. Laravel and Symfony are not more or less enterprise ready than micro frameworks.
And because those frameworks are known outside of the developer community, is it also an easier sale.
If I had the time and backing, I would go past micro frameworks and take the best packages to make a custom framework based on the requirements of the project.