PHP Forms Validate URL

Form validation is a necessary process that must be done before submitting the data to the database. Any time a user submits a URL, it becomes crucial to investigate whether the given URL is valid or not. We can use PHP to validate the URLs that are submitted through an HTML form.

Using filter_var( ) Function

To validate a URL, the first approach is to use the filter_var( ) method with the FILTER_VALIDATE_URL filter. This method is widely used in PHP to filter a variable with a specific filter. It ensures that URLs are correctly formatted and secure, thus reducing the chances of security vulnerabilities.

Example: Implementation to validate URL in PHP Forms using filter_var( ).

<?php
  
// Taking a sample URL
$url = "https://www.example.in";

// Checking if the URL is valid or not
if (filter_var($url, FILTER_VALIDATE_URL)) {
    echo "$url is a VALID URL";
} else {
    echo "$url is a INVALID URL";
}
?>

https://www.example.in is a VALID URL

Using preg_match( ) Function

The preg_match( ) method is commonly used to search the given string using a pattern. This pattern is created using regular expression.

Example: Implementation to validate URL in PHP Forms using preg_match( )

<?php
// Taking a sample URL

$url = "https://www.example.in";

// Checking if the URL is valid or not
if (
    preg_match(
"/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i",
        $url
    )
) {
    echo "$url is a VALID URL";
} else {
    echo "$url is a INVALID URL";
}
?>

https://www.example.in is a VALID URL