WhatsApp is one of a few messaging platforms that lets you delete a message after you've sent it. Skype is another one worth mentioning, though we're sure that far more people actually use WhatsApp. The messenger platform introduced the feature back in October of last year and allows someone to delete a message ".for everyone" within 7 minutes of the message being sent. Of course, the recipient(s) would not see the message, but would see a message deleted' placeholder replace the deleted message. WhatsApp has quietly updated this time window of which you may delete a message after...
Source: https://www.gsmarena.com/whatsapp_time_limit_for_deleting_messages_increases_to_over_an_hour-news-30053.php