sanitize_email( string $email ): string

3831function sanitize_email( $email ) {3832	// Test for the minimum length the email can be.3833	if ( strlen( $email ) < 6 ) {3834		/**3835		 * Filters a sanitized email address.3836		 *3837		 * This filter is evaluated under several contexts, including 'email_too_short',3838		 * 'email_no_at', 'local_invalid_chars', 'domain_period_sequence', 'domain_period_limits',3839		 * 'domain_no_periods', 'domain_no_valid_subs', or no context.3840		 *3841		 * @since 2.8.03842		 *3843		 * @param string $sanitized_email The sanitized email address.3844		 * @param string $email           The email address, as provided to sanitize_email().3845		 * @param string|null $message    A message to pass to the user. null if email is sanitized.3846		 */3847		return apply_filters( 'sanitize_email', '', $email, 'email_too_short' );3848	}3849 3850	// Test for an @ character after the first position.3851	if ( false === strpos( $email, '@', 1 ) ) {3852		/** This filter is documented in wp-includes/formatting.php */3853		return apply_filters( 'sanitize_email', '', $email, 'email_no_at' );3854	}3855 3856	// Split out the local and domain parts.3857	list( $local, $domain ) = explode( '@', $email, 2 );3858 3859	/*3860	 * LOCAL PART3861	 * Test for invalid characters.3862	 */3863	$local = preg_replace( '/[^a-zA-Z0-9!#$%&\'*+\/=?^_`{|}~\.-]/', '', $local );3864	if ( '' === $local ) {3865		/** This filter is documented in wp-includes/formatting.php */3866		return apply_filters( 'sanitize_email', '', $email, 'local_invalid_chars' );3867	}3868 3869	/*3870	 * DOMAIN PART3871	 * Test for sequences of periods.3872	 */3873	$domain = preg_replace( '/\.{2,}/', '', $domain );3874	if ( '' === $domain ) {3875		/** This filter is documented in wp-includes/formatting.php */3876		return apply_filters( 'sanitize_email', '', $email, 'domain_period_sequence' );3877	}3878 3879	// Test for leading and trailing periods and whitespace.3880	$domain = trim( $domain, " \t\n\r\0\x0B." );3881	if ( '' === $domain ) {3882		/** This filter is documented in wp-includes/formatting.php */3883		return apply_filters( 'sanitize_email', '', $email, 'domain_period_limits' );3884	}3885 3886	// Split the domain into subs.3887	$subs = explode( '.', $domain );3888 3889	// Assume the domain will have at least two subs.3890	if ( 2 > count( $subs ) ) {3891		/** This filter is documented in wp-includes/formatting.php */3892		return apply_filters( 'sanitize_email', '', $email, 'domain_no_periods' );3893	}3894 3895	// Create an array that will contain valid subs.3896	$new_subs = array();3897 3898	// Loop through each sub.3899	foreach ( $subs as $sub ) {3900		// Test for leading and trailing hyphens.3901		$sub = trim( $sub, " \t\n\r\0\x0B-" );3902 3903		// Test for invalid characters.3904		$sub = preg_replace( '/[^a-z0-9-]+/i', '', $sub );3905 3906		// If there's anything left, add it to the valid subs.3907		if ( '' !== $sub ) {3908			$new_subs[] = $sub;3909		}3910	}
When	Instructions	Calls it makes
always	11–15	`apply_filters()`
always	28–37	`explode(), apply_filters()`
`$local !== "" && $domain !== ""`	45–56	`explode(), explode(), apply_filters()`
PHP	Compiled	Executed	Branches	Notes
8.6-dev	115	11–56	10
8.5	115	11–56	10
8.4	115	11–56	10	21 fewer instructions than PHP 8.3
8.3	136	11–71	10
8.2	136	11–71	10
8.1	136	11–71	10
7.4	136	11–71	10