Using WordPress ‘file_is_valid_image()’ PHP function

by

The file_is_valid_image() WordPress PHP function is used to validate if a given file is an image.

Usage

To use the file_is_valid_image() function, pass a string representing the file path as the argument. If the file at the specified path is a valid image, the function will return true. Otherwise, it will return false.

// Checks if the file is a valid image
$isValid = file_is_valid_image('/path/to/your/image.jpg');

// Outputs: true or false
echo $isValid;

Parameters

  • $path (string) – The file path of the image to validate.

More information

See WordPress Developer Resources: file_is_valid_image()

Examples

Validate a JPEG Image

In this example, we are validating a JPEG image. If the image is valid, it will output ‘true’.

$path = '/path/to/your/image.jpg';
$isValid = file_is_valid_image($path);
echo $isValid; // Outputs: true or false

Validate a PNG Image

This example shows how to validate a PNG image. 

$path = '/path/to/your/image.png';
$isValid = file_is_valid_image($path);
echo $isValid; // Outputs: true or false

Validate a Non-existent Image

This example demonstrates how the function behaves when the image does not exist. It should return false. 

$path = '/path/to/your/nonexistent.jpg';
$isValid = file_is_valid_image($path);
echo $isValid; // Outputs: false

Validate a Non-image File

In this example, we are validating a text file. As a text file is not an image, it should return false.

$path = '/path/to/your/file.txt';
$isValid = file_is_valid_image($path);
echo $isValid; // Outputs: false

Validate an Image with Uppercase Extension

This example demonstrates how to validate an image file with an uppercase extension. The function treats file extensions case-insensitively. 

$path = '/path/to/your/image.JPG';
$isValid = file_is_valid_image($path);
echo $isValid; // Outputs: true or false