Using WordPress ‘image_memory_limit’ PHP filter

The image_memory_limit WordPress PHP Filter allows you to modify the memory limit allocated for image manipulation.

Usage

add_filter('image_memory_limit', 'my_custom_image_memory_limit');
function my_custom_image_memory_limit($filtered_limit) {
    // your custom code here
    return $filtered_limit;
}

Parameters

  • $filtered_limit (int|string) – Maximum memory limit to allocate for images. Default is WP_MAX_MEMORY_LIMIT or the original php.ini memory_limit, whichever is higher. Accepts an integer (bytes), or a shorthand string notation, such as ‘256M’.

More information

See WordPress Developer Resources: image_memory_limit

Examples

Increase image memory limit to 512M

Increase the memory limit allocated for image manipulation to 512M.

add_filter('image_memory_limit', 'increase_image_memory_limit');
function increase_image_memory_limit($filtered_limit) {
    return '512M';
}

Double the current memory limit

Double the current memory limit for image manipulation.

add_filter('image_memory_limit', 'double_image_memory_limit');
function double_image_memory_limit($filtered_limit) {
    $current_limit = wp_convert_hr_to_bytes($filtered_limit);
    return 2 * $current_limit . 'B';
}

Set image memory limit based on user role

Set the image memory limit based on the user role. Administrators get a higher limit.

add_filter('image_memory_limit', 'set_image_memory_limit_by_role');
function set_image_memory_limit_by_role($filtered_limit) {
    if (current_user_can('administrator')) {
        return '512M';
    }
    return '256M';
}

Limit image memory to half the server’s memory limit

Limit the image memory to half of the server’s memory limit.

add_filter('image_memory_limit', 'limit_image_memory_to_half_server_limit');
function limit_image_memory_to_half_server_limit($filtered_limit) {
    $server_memory_limit = wp_convert_hr_to_bytes(ini_get('memory_limit'));
    return intval($server_memory_limit / 2) . 'B';
}

Log image memory limit changes

Log any changes to the image memory limit in a custom log file.

add_filter('image_memory_limit', 'log_image_memory_limit_changes', 10, 2);
function log_image_memory_limit_changes($filtered_limit, $original_limit) {
    if ($filtered_limit !== $original_limit) {
        error_log("Image memory limit changed from $original_limit to $filtered_limit");
    }
    return $filtered_limit;
}