PHP FILTER_VALIDATE_URL Filter
Example
Check if the variable $url is a valid URL:
<?php
$url = "http://www.w3schools.com";
if (!filter_var($url,
FILTER_VALIDATE_URL) === false) {
echo("$url is a
valid URL");
} else {
echo("$url is
not a valid URL");
}
?>
Run example »
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 = "http://www.w3schools.com";
// Remove all illegal
characters from a url
$url = filter_var($url, FILTER_SANITIZE_URL);
// Validate url
if (!filter_var($url, FILTER_VALIDATE_URL) === false)
{
echo("$url is a valid URL");
} else {
echo("$url is not a valid URL");
}
?>
Run example »
Example 2
Here, the URL is required to have a query string to be valid:
<?php
$url = "http://www.w3schools.com";
if (!filter_var($url, FILTER_VALIDATE_URL,
FILTER_FLAG_QUERY_REQUIRED) === false)
{
echo("$url is a valid URL");
} else {
echo("$url is not a valid URL");
}
?>
Run example »
PHP Filter Reference
