Facebook has a new dark mode for Messenger, and it's a true OLED black theme. It's was hidden away in earlier versions and you needed to either run a root hack or send a moon emoji to activate it — but now, you can enable dark mode by toggling a simple switch in Facebook Messenger's settings.
To begin, make sure you're running the latest version of Facebook Messenger (version 126.96.36.199.97 or higher). You can update the app by heading to your phone's respective app store, or you can tap one of the links below and select "Update."
Now, open Messenger and tap either the silhouette icon or your profile picture in the top-left corner of the main screen to open the app's settings. From there, just enable the "Dark Mode" toggle switch towards the top of the menu — it's as simple as that!
Once enabled, it's a true black dark mode, so you'll save battery life on phones with OLED screens like the iPhone XS or Galaxy S10. The theme was a work in progress previously, but now, it seems to be complete. So no more issues where there's black text overlaid on a black background — instead, it's a fully functional true dark mode for Messenger.