$re = '/https:\/\/tenor\.com\/(?:[a-z]{2}(?:-[A-Z]{2})?\/)?view\/(?P<image_slug>[a-zA-Z0-9%-]+-(?P<image_id>\d+))/m';
$str = 'https://tenor.com/es-ES/view/baka-idiot-anime-gif-16811539
https://tenor.com/bg/view/baka-idiot-anime-gif-16811539
https://tenor.com/de/view/baka-idiot-anime-gif-16811539
https://tenor.com/zh-CN/view/baka-idiot-anime-gif-16811539
https://tenor.com/view/frieren-%E8%91%AC%E9%80%81%E3%81%AE%E3%83%95%E3%83%AA%E3%83%BC%E3%83%AC%E3%83%B3-sousou-no-frieren-sousou-beyond-journey%27s-end-gif-13214487266596803271';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php