Creating SEO friendly URL

2018-04-22 12:30:20 PHP, SEO, EN

Deutsche Version: String SEO optimieren (creating SEO friendly URL)

This is about how to create a SEO Friendly URL from a string with a PHP Function

The function seofy () below creates a friendly version of a string. Umlauts and other characters not contained in the ASCII character set are either reduced to the basic form equivalent (e. g.: é becomes e and ú becomes u) or completely converted (e. g.: ß becomes ss and ü becomes ue).

This succeeds on the one hand because the php function preg_replace performs the replacement by means of unicode - i. e. Unicode Regular Expressions - and on the other hand because an approximate translation is attempted by means of php function iconv with option TRANSLIT.

Quote php. net about iconv and TRANSLIT:

If you append the character string //TRANSLIT to out_charset, transliteration is activated. This means that a character that cannot be displayed in the target character set can be approximated with one or more similar-looking characters.[…]


 * prepares a string optimized for SEO
 * @param string $sString 
 * @return string $sString SEO optimized string
function seofy ($sString = '')
    $sString = preg_replace ('/[^\pL\d_]+/u', '-', $sString);
    $sString = trim ($sString, "-");
    $sString = iconv ('utf-8', "us-ascii//TRANSLIT", $sString);
    $sString = strtolower ($sString);
    $sString = preg_replace ('/[^-a-z0-9_]+/', '', $sString);

    return $sString;



echo seofy('Straßenfest in München');          // => strassenfest-in-muenchen
echo seofy('José Ignacio López de Arriortúa'); // => jose-ignacio-lopez-de-arriortua