We already know that the new Facebook Messenger update will axe the Discover tab, and today we're learning a bit more about the improvements packed into the update.

Facebook confirmed today that Messenger for iOS has been rebuilt from the ground up. Codenamed "Project Lightspeed", the update will help Messenger load twice as fast as previous versions and it'll take up one-fourth of its original size. 

The updated Messenger has been made simpler, too. The contact list has been reduced from 40 versions to one that works consistently across the app.

Facebook goes into more detail on how it made Messenger for iOS lighter and faster over on its Engineering Blog if you're interested in more nitty-gritty details. One notable detail is that Facebook reduced the core Messenger code by 84%, dropping it from 1.7 million lines of code to 360,000.

This updated Messenger for iOS app is starting its rollout today and will continue hitting users over the next few weeks.