Install PHP and its extensions for Laravel on Debian 13

Laravel 13 asks for PHP 8.2 at the very least, plus a handful of extensions. Good news: Debian 13 “trixie” ships PHP 8.4 in its official repositories, which makes the third-party Sury repository pointless in the ordinary case.

Steps run on a clean Debian 13 container, on 2 September 2026. This chapter is part of installing Laravel on a Debian server, in the Web development path.

Check what your Debian already offers

Before adding a single repository, look at what the distribution provides:

sudo apt update
apt-cache policy php-cli

php-cli:
  Installed: (none)
  Candidate: 2:8.4+96
  Version table:
     2:8.4+96 500
        500 http://deb.debian.org/debian trixie/main arm64 Packages

PHP 8.4 is available. That is well beyond what Laravel 13 needs, and it spares you an external repository to maintain. Which PHP version each Debian release ships:

Install PHP and the extensions

A single command covers the base Laravel requires, plus the database drivers:

sudo apt install -y php-cli php-fpm \
  php-mbstring php-xml php-curl php-zip \
  php-bcmath php-intl \
  php-mysql php-sqlite3 \
  unzip curl ca-certificates

Two common extensions are missing from that list, because they depend on your architecture choices: php-redis, covered in the chapter on Redis, and php-gd or php-imagick for image processing.

Check the version you ended up with:

php -v

PHP 8.4.24 (cli) (built: Jul 31 2026 05:11:11) (NTS)

Then make sure every extension Laravel expects answers for itself:

for e in ctype curl dom fileinfo filter hash mbstring openssl \
         pcre pdo session tokenizer xml bcmath intl zip; do
  printf "%-10s %s\n" "$e" "$(php -m | grep -qix "$e" && echo OK || echo MANQUANT)"
done

On the test install, all sixteen lines return OK. Several of those extensions are compiled into Debian’s PHP binary and have no package of their own: they show up in php -m all the same.

Two packages that keep being recommended by mistake

php -r 'echo implode(", ", PDO::getAvailableDrivers()), PHP_EOL;'

mysql, sqlite

If mysql is not in that list, Laravel will not be able to connect to MySQL or MariaDB, whatever you put in the .env file.

Tune PHP for a web application

Two files sit side by side, with different values: the command-line one and the web server one. Editing the wrong one is a classic source of confusion.

/etc/php/8.4/cli/php.ini    # artisan, composer, scheduled tasks
/etc/php/8.4/fpm/php.ini    # requests served by nginx or Apache

The settings that matter for a Laravel application live in the FPM file:

memory_limit = 256M
upload_max_filesize = 20M
post_max_size = 21M
max_execution_time = 60

post_max_size has to stay above upload_max_filesize, otherwise an upload at the maximum size is rejected before it ever reaches the application. Then reload the service, without which the values stay exactly as they were:

sudo systemctl reload php8.4-fpm
php -i | grep memory_limit          # CLI value
sudo -u www-data php-fpm8.4 -i | grep memory_limit

With PHP in place, the next step is installing Composer.

Install another PHP version with the Sury repository

This detour is only worth taking if you are after a version Debian does not provide: PHP 8.5 on Debian 13, or PHP 8.2 on a Debian 11. The method has changed: apt-key is gone as of Debian 12, so a dedicated keyring is required.

sudo apt install -y curl ca-certificates
sudo curl -fsSLo /etc/apt/keyrings/php.gpg https://packages.sury.org/php/apt.gpg

echo "deb [signed-by=/etc/apt/keyrings/php.gpg] https://packages.sury.org/php/ $(. /etc/os-release && echo $VERSION_CODENAME) main" \
  | sudo tee /etc/apt/sources.list.d/php.list

sudo apt update
sudo apt install -y php8.5-cli php8.5-fpm php8.5-mbstring php8.5-xml php8.5-curl php8.5-zip php8.5-bcmath php8.5-intl php8.5-mysql

With several versions installed, pick the one that answers to the php command:

sudo update-alternatives --config php