Built-In Web Server

PHP includes a small development web server. It lets you run a local PHP site without installing Nginx, Apache, Caddy, or PHP-FPM.

Use it for learning, demos, small local projects, and quick HTTP checks. Do not use it as a production server.

Starting The Server

The basic command is:

php -S 127.0.0.1:8000

That starts a local server on http://127.0.0.1:8000. Press Ctrl+C in the terminal to stop it.

Most projects should use a public document root:

php -S 127.0.0.1:8000 -t public

The -t public option means the server should serve files from the public directory. That keeps source files, configuration, and vendor code outside the web root.

A Minimal public/index.php

Create public/index.php:

<?php

declare(strict_types=1);

header('Content-Type: text/plain');

echo 'Hello from PHP' . PHP_EOL;
echo 'SAPI: ' . PHP_SAPI . PHP_EOL;

// Browser output:
// Hello from PHP
// SAPI: cli-server

Start the server:

php -S 127.0.0.1:8000 -t public

Then open:

http://127.0.0.1:8000/

PHP_SAPI reports cli-server because the built-in server runs from the CLI runtime.

Checking Request Information

The built-in server gives you normal web request values in $_SERVER.

<?php

declare(strict_types=1);

header('Content-Type: application/json');

echo json_encode([
    'method' => $_SERVER['REQUEST_METHOD'] ?? 'unknown',
    'uri' => $_SERVER['REQUEST_URI'] ?? 'unknown',
    'query' => $_SERVER['QUERY_STRING'] ?? '',
    'sapi' => PHP_SAPI,
], JSON_PRETTY_PRINT | JSON_THROW_ON_ERROR);
echo PHP_EOL;

// Example URL:
// http://127.0.0.1:8000/?page=2
//
// Prints:
// {
//     "method": "GET",
//     "uri": "/?page=2",
//     "query": "page=2",
//     "sapi": "cli-server"
// }

This is useful when learning how HTTP requests reach PHP.

Static Files

The built-in server serves static files directly when they exist under the document root. For example:

public/style.css
public/images/logo.png

Those files can be requested as:

http://127.0.0.1:8000/style.css
http://127.0.0.1:8000/images/logo.png

If a file does not exist, the server may route the request to a PHP script depending on how you started it.

Router Scripts

A router script gives you more control. It can let existing static files pass through and send everything else to index.php.

Create router.php in the project root:

<?php

declare(strict_types=1);

$path = parse_url($_SERVER['REQUEST_URI'] ?? '/', PHP_URL_PATH);
$file = __DIR__ . '/public' . $path;

if (is_string($path) && $path !== '/' && is_file($file)) {
    return false;
}

require __DIR__ . '/public/index.php';

Start the server with the router:

php -S 127.0.0.1:8000 router.php

Returning false tells the built-in server to serve the requested static file itself. Otherwise the router includes the front controller.

Binding Address

Use 127.0.0.1 for local-only development:

php -S 127.0.0.1:8000 -t public

Binding to 0.0.0.0 listens on all network interfaces:

php -S 0.0.0.0:8000 -t public

Only use 0.0.0.0 when you deliberately want another device or container to reach the server. Do not expose the built-in server to the public internet.

Limitations

The built-in server is not a production replacement for Nginx, Apache, Caddy, or a managed runtime.

Important limitations:

• it is designed for development
• it does not replace proper TLS, static file, caching, compression, or process management setup
• it runs as the current user
• it uses the CLI PHP configuration
• it does not prove PHP-FPM is configured correctly

If production uses PHP-FPM behind Nginx, a local built-in server can help you develop routes, but it cannot verify the production web server configuration.

What You Should Be Able To Do

After this lesson, you should be able to start the built-in server, choose a document root, inspect request information, use a router script, and explain why the built-in server is for development only.

For junior PHP work, this matters because the built-in server is the fastest way to see PHP through HTTP while learning. The professional habit is knowing where its usefulness ends.