FILTER_SANITIZE_EMAIL constant in PHP

The FILTER_SANITIZE_EMAIL constant removes all characters from a string that are not allowed in an email address according to RFC standards. This filter is useful for cleaning user input before validation or storage.

Syntax

filter_var($email, FILTER_SANITIZE_EMAIL)

Parameters

The filter_var() function accepts the following parameters when used with FILTER_SANITIZE_EMAIL −

• $email − The email string to be sanitized
• FILTER_SANITIZE_EMAIL − The filter constant that removes illegal email characters

Return Value

Returns the sanitized email string with illegal characters removed, or FALSE on failure.

Example

The following example demonstrates how FILTER_SANITIZE_EMAIL removes invalid characters from an email address −

<?php
    $myemail = "abc@demo//.com";
    $sanitized = filter_var($myemail, FILTER_SANITIZE_EMAIL);
    echo "Original: " . $myemail . "<br>";
    echo "Sanitized: " . $sanitized;
?>

Original: abc@demo//.com
Sanitized: abc@demo.com

Multiple Invalid Characters

Here's an example showing sanitization of an email with multiple types of invalid characters −

<?php
    $email = "user@exa<mple>.c om!";
    $clean_email = filter_var($email, FILTER_SANITIZE_EMAIL);
    echo "Original: " . $email . "<br>";
    echo "Sanitized: " . $clean_email;
?>

Original: user@exa<mple>.c om!
Sanitized: user@example.com

Conclusion

FILTER_SANITIZE_EMAIL effectively removes invalid characters from email strings, making them RFC−compliant. Always combine sanitization with validation using FILTER_VALIDATE_EMAIL for complete email processing.