Doesn't parse serialized PHP

I paste the following this data to JSON.pub, but it doesn’t unserialize properly. The data is a valid serialized string in PHP.

a:2:{i:0;a:6:{s:3:"_id";s:15:"text_u6e04e4igk";s:4:"type";s:4:"text";s:2:"id";s:5:"text2";s:4:"name";s:4:"Text";s:12:"text_limiter";a:1:{s:5:"limit";i:20;}s:10:"save_field";b:1;}i:1;a:6:{s:3:"_id";s:19:"textarea_udxkec8g69";s:4:"type";s:8:"textarea";s:2:"id";s:8:"textarea";s:4:"name";s:8:"Textarea";s:4:"rows";i:4;s:10:"save_field";b:1;}}