How to run a Symfony project locally

A Symfony application needs a local HTTP entry point while controllers, templates, forms, and services are being changed. The Symfony CLI includes a development web server that starts the project from the terminal and prints the loopback URL that the browser or a smoke-test request can reach.

The local server is for development only. It listens on 127.0.0.1 by default, uses the PHP version available on the workstation, and can run in the background while editor, console, and browser checks continue against the same project.

An existing project still needs its Composer dependencies and project-specific environment values before the server can answer. A 200 response from a real route proves that the PHP front controller, routing layer, and controller response are working; a fresh skeleton without a homepage can still return 404 at / until an application route exists.

1. Open the Symfony project directory.

   $ cd ~/projects/acme-app

   Use the directory that contains composer.json, bin/console, and the public/ document root.

2. Install the project dependencies.

   $ composer install
   Installing dependencies from lock file (including require-dev)
   Verifying lock file contents can be installed on current platform.
   Nothing to install, update or remove
   Generating autoload files
   Executing script cache:clear [OK]
   Executing script assets:install public [OK]
   Executing script importmap:install [OK]

3. Confirm that the Symfony console can boot the project.

   $ php bin/console about
    -------------------- ---------------------------------
     Symfony
    -------------------- ---------------------------------
     Version              v8.1.0
   ##### snipped #####
     Environment          dev
     Debug                true
   ##### snipped #####
     PHP
    -------------------- ---------------------------------
     Version              8.5.7
   ##### snipped #####

   The about command reads the same kernel that local HTTP requests will use. Fix dependency, environment, or cache errors here before starting the web server.

4. Start the local web server on an explicit HTTP port.

   $ symfony server:start --port=8001 --no-tls --daemon
   [OK] Web server listening
        The Web server is using PHP FPM 8.5.7
        http://127.0.0.1:8001
   
   Stream the logs via symfony server:log

   The Symfony local web server is optimized for development and must not replace Nginx, Apache, or a production runtime.

5. Check the local server status.

   $ symfony server:status
   Local Web Server
       Listening on http://127.0.0.1:8001
       The Web server is using PHP FPM 8.5.7
   
   Local Domains
   
   Workers
       PID 3912: php-fpm --nodaemonize
   
   Environment Variables
       None

   Use another unused port if 8001 is already in use. The default Symfony port is 8000, but an explicit port keeps the smoke test URL predictable.

6. Request an existing application route.

   $ curl --fail --silent --show-error http://127.0.0.1:8001/healthz
   local symfony ok

   Replace /healthz with a route that exists in the project. If no route exists yet, add a small route first, then repeat the request.
   Related: How to create a Symfony route

7. Stop the local server when the local check is finished.

   $ symfony server:stop
   Stopping PHP-FPM
   Stopping Web Server
   
   [OK] Stopped 2 process(es) successfully