PHP FILTER_VALIDATE_URL Filter

Example

Check if the variable $url is a valid URL:

<?php
$url = "https://www.w3schools.com";

if (filter_var($url, FILTER_VALIDATE_URL)) {
echo("$url is a valid URL");
} else {
echo("$url is not a valid URL");
}
?>

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Definition and Usage

The FILTER_VALIDATE_URL filter validates a URL.

Possible flags:

FILTER_FLAG_SCHEME_REQUIRED - URL must be RFC compliant (like http://example)
FILTER_FLAG_HOST_REQUIRED - URL must include host name (like http://www.example.com)
FILTER_FLAG_PATH_REQUIRED - URL must have a path after the domain name (like www.example.com/example1/)
FILTER_FLAG_QUERY_REQUIRED - URL must have a query string (like "example.php?name=Peter&age=37")

More Examples

The example below both sanitizes and validates an URL:

Example 1

First remove all illegal characters from the $url variable, then check if it is a valid URL:

<?php
$url = "https://www.w3schools.com";

// Remove all illegal characters from a url
$url = filter_var($url, FILTER_SANITIZE_URL);

// Validate url
if (filter_var($url, FILTER_VALIDATE_URL)) {
echo("$url is a valid URL");
} else {
echo("$url is not a valid URL");
}
?>

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Example 2

Here, the URL is required to have a query string to be valid:

<?php
$url = "https://www.w3schools.com";

if (filter_var($url, FILTER_VALIDATE_URL, FILTER_FLAG_QUERY_REQUIRED)) {
echo("$url is a valid URL");
} else {
echo("$url is not a valid URL");
}
?>

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❮ PHP Filter Reference