Such encryption means that no one other than the sender and the recipient — not even Meta — can decipher people’s messages. Encrypted chats, first introduced as an optional feature in Messenger in 2016, will now be the standard for all users going forward, according to Messenger head Loredana Crisan.

“This has taken years to deliver because we’ve taken our time to get this right,” Crisan wrote in a blog post. “Our engineers, cryptographers, designers, policy experts and product managers have worked tirelessly to rebuild Messenger features from the ground up.”