If your server does not have ImageMagick or GD installed or enabled, follow these steps based on your operating system to install and configure them.

Installing ImageMagick

For Ubuntu/Debian

1 Update the Package List
sudo apt update
2 Install ImageMagick
sudo apt install imagemagick php-imagick -y
3 Restart the Web Server

For Apache:

sudo systemctl restart apache2

For Nginx with PHP-FPM:

sudo systemctl restart php7.x-fpm
4 Verify Installation
php -m | grep imagick

If installed, imagick will appear in the output.

For CentOS/RHEL

1 Enable the EPEL Repository
sudo yum install epel-release -y
2 Install ImageMagick
sudo yum install ImageMagick ImageMagick-devel php-pecl-imagick -y
3 Restart the Web Server
sudo systemctl restart httpd

or for PHP-FPM:

sudo systemctl restart php-fpm
4 Verify Installation
php -m | grep imagick

For Windows Servers

1 Download ImageMagick

Download the ImageMagick binary for Windows from the official ImageMagick website.

2 Install the binary

Install the binary and add its path to the system environment variables.

3 Enable the imagick extension in php.ini
extension=imagick
4 Restart the web server

Installing GD

For Ubuntu/Debian

1 Update the Package List
sudo apt update
2 Install the GD Library
sudo apt install php-gd -y
3 Restart the Web Server

For Apache:

sudo systemctl restart apache2

For Nginx with PHP-FPM:

sudo systemctl restart php7.x-fpm
4 Verify Installation
php -m | grep gd

If installed, gd will appear in the output.

For CentOS/RHEL

1 Install the GD Library
sudo yum install php-gd -y
2 Restart the Web Server
sudo systemctl restart httpd

or for PHP-FPM:

sudo systemctl restart php-fpm
3 Verify Installation
php -m | grep gd

For Windows Servers

1 Enable the gd extension in php.ini
extension=gd
2 Restart the web server

Enable Extensions in PHP

Ensure that the imagick and gd extensions are enabled in php.ini:

  1. Locate the php.ini file:
    2. php --ini
  2. Open the file in a text editor:
    3. sudo nano /etc/php/7.x/apache2/php.ini # For Apache
    sudo nano /etc/php/7.x/fpm/php.ini # For PHP-FPM
  3. Uncomment (or add) the lines:
    4. extension=gd
    extension=imagick
  4. Save and exit, then restart your web server.

Verify in WordPress

  1. Go to your WordPress Admin Dashboard.
  2. Navigate to Media > Add New.
  3. Upload an image and test resizing functionality.

Troubleshooting

GD or ImageMagick Not Detected

  • Ensure the correct PHP version is used:
    • php -v
  • Verify the PHP extensions directory:
    • php -i | grep extension_dir

Web Server Not Restarting

Check error logs for issues:

sudo tail -f /var/log/apache2/error.log # For Apache
sudo tail -f /var/log/nginx/error.log # For Nginx

Additional Notes

  • ImageMagick is preferred for advanced image processing.
  • GD is recommended if you need a lightweight solution.