How to check PHP version

Using the correct PHP version is important to ensure compatibility with your code. Newer versions of PHP offer additional features, but older code might not work correctly with them. It's necessary to check your system’s PHP version before making any changes or updates.

There are several ways to check the PHP version on your system. You can use the command line or execute specific PHP functions in your code. These methods help you confirm that your environment meets the requirements of your project.

Verifying the PHP version is also important when managing server environments. Different operating systems, like Ubuntu, have different commands for checking installed packages. Being familiar with these commands ensures that you can maintain and troubleshoot your PHP setup effectively.

1. Run php -v from the command line.

   $ php -v
   PHP 7.4.3 (cli) (built: May 26 2020 12:24:22) ( NTS )
   Copyright (c) The PHP Group
   Zend Engine v3.4.0, Copyright (c) Zend Technologies
       with Zend OPcache v7.4.3, Copyright (c), by Zend Technologies

2. Run php -i from the command line.

   $ php -i | grep "PHP Version"
   PHP Version => 7.4.3
   PHP Version => 7.4.3

3. Print PHP_VERSION_ID from PHP script.

   <?php 
   	echo PHP_VERSION_ID;
   	//Sample output: 70403
   ?>

4. Print phpversion() output from PHP script.

   <?php 
   	echo phpversion();
   	//Sample output: 7.4.3
   ?>

5. View from phpinfo() output.

   <?php 
   	phpinfo();
   ?>

   

6. Query your package manager where the PHP packages are installed from.

   $ apt show php
   Package: php
   Version: 2:7.4+75
   Priority: optional
   Section: php
   Source: php-defaults (75)
   Origin: Ubuntu
   Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
   Original-Maintainer: Debian PHP Maintainers <team+pkg-php@tracker.debian.org>
   Bugs: https://bugs.launchpad.net/ubuntu/+filebug
   Installed-Size: 13.3 kB
   Depends: php7.4
   Download-Size: 2,712 B
   APT-Sources: http://jp.archive.ubuntu.com/ubuntu focal/main amd64 Packages
   Description: server-side, HTML-embedded scripting language (default)
    PHP (recursive acronym for PHP: Hypertext Preprocessor) is a widely-used
    open source general-purpose scripting language that is especially suited
    for web development and can be embedded into HTML.
    .
    This package is a dependency package, which depends on latest stable
    PHP version (currently 7.4).

   Package manager query comand for different operating systems and distributions:

   Platform	Command
   homebrew	$ brew list --versions php
   Debian, Ubuntu	$ apt show php
   CentOS, RedHat, Fedora	$ dnf info httpd