$re = '/(?s)(\[)(\d+\.\d+\.\d+)(,)(\s)(\d+:\d+:\d+)(])(\s)([^:]+)(:)(.*?)(?=\[\d+\.\d+\.\d+,\s\d+:\d+:\d+]|\Z)/m';
$str = ' [12.06.17, 13:18:36] Name1: Test test test
[12.06.17, 13:20:20] Name2 ❤️: blabla
[12.06.17, 13:20:44] Name2 ❤️: words words words
words
words
words
[12.06.17, 13:29:03] Name1: more words more words
[12.06.17, 13:38:52] Name3 Surname Nickname: 👍🏼
[12.06.17, 13:40:37] Name1: message?';
preg_match_all($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