Event-driven, non-blocking I/O with PHP

ReactPHP is a low-level library for event-driven programming in PHP. At its core is an event loop, on top of which it provides low-level utilities, such as: Streams abstraction, async DNS resolver, network client/server, HTTP client/server and interaction with processes. Third-party libraries can use these components to create async network clients/servers and more.


// $ composer require react/http react/socket # install example using Composer
// $ php example.php # run example on command line, requires no additional web server

require __DIR__ . '/vendor/autoload.php';

$http = new React\Http\HttpServer(function (Psr\Http\Message\ServerRequestInterface $request) {
    return React\Http\Message\Response::plaintext(
        "Hello World!\n"

$socket = new React\Socket\SocketServer('');

echo "Server running at" . PHP_EOL;

This simple web server written in ReactPHP responds with "Hello World!" for every request.

ReactPHP is production ready and battle-tested with millions of installations from all kinds of projects around the world.

Its event-driven architecture makes it a perfect fit for efficient network servers and clients handling hundreds or thousands of concurrent connections, long-running applications and many other forms of cooperative multitasking with non-blocking I/O operations.

What makes ReactPHP special is its vivid ecosystem with hundreds of third-party libraries allowing you to integrate with many existing systems, such as common network services, database systems and other third-party APIs.

ReactPHP is non-blocking by default. Use workers for blocking I/O.

The event loop is based on the reactor pattern (hence the name) and strongly inspired by libraries such as EventMachine (Ruby), Twisted (Python) and Node.js (V8).

  • Production ready and battle-tested.
  • Rock-solid with stable long-term support (LTS) releases.
  • Requires no extensions and runs on any platform - no excuses!
  • Takes advantage of optional extensions to get better performance when available.
  • Supports latest version of PHP 8+ and PHP 7+ for best performance and support.
  • Still supports legacy PHP 5.3+ and HHVM for maximum compatibility.
  • Well designed and reusable components.
  • Decoupled parts so they can be replaced by alternate implementations.
  • Carefully tested (unit & functional).
  • Promotes standard PSRs where possible for maximum interoperability.
  • Aims to be technology neutral, so you can use your preferred application stack.
  • Small core team of professionals supported by large network of outside contributors.

Core Components

Network Components

Utility Components

Legacy Components

Built with ReactPHP

And many more on our wiki page »



Get to know the people behind ReactPHP

We're a small core team of professionals. We help manage, maintain and steer the project.
But ReactPHP isn't just us. We're proudly supported by a large network of outside contributors from all over the world.


Do you have a question and need help with ReactPHP?
Don't worry, we're here to help!

As a first step, check the elaborate documentation that comes with each component (see links to individual documentation for each component above). If you find your question is not answered within the documentation, there's a fair chance that it may be relevant to more people. Please do not hesitate to file your question as an issue in the relevant component so others can also participate.

You can find our official channel at reactphp/reactphp on Gitter.im. Many of us are available in this channel, so many questions get answered in a few minutes to some hours. We also use this channel to announce all new releases and ongoing development efforts.

Also follow @reactphp on Twitter for updates. We use this mostly for noteworthy, bigger updates and to keep the community updated about ongoing development efforts. You can always use the #reactphp hashtag if you have anything to share!

We're a very open project and we prefer public communication whenever possible, so that more people can participate and help getting the best solutions available. At the same time, we realize that some things are better addressed in private.

Whether you just want to say thank you, want to report a security issue or want to help sponsor a certain feature development, you can reach out to the core team in private by sending an email to [email protected]. Please keep in mind that we're a small team of volunteers and do our best to support anybody reaching out.

Do you want to support ReactPHP? Awesome! Let's start with letting the the world know why you think ReactPHP is awesome and try to help others getting on board! Send a tweet, write a blog post, give a talk at your local user group or conference or even write a book. There are many ways you can help. You can always reach out to us in private and help others in our support channels. Thank you!