We love easter eggs, and this latest one in the Facebook Messenger app is one of our favourites we've ever tried.

Easter eggs are hidden features in apps or services that you can unlock with a simple trick. We've found quite a few of them in Facebook Messenger over the years, including this secret basketball game. Now, thanks to eagle-eyed users at Android Police and 9to5Mac, we've learned Messenger has a new dark mode toggle that can be found and activated - if you send someone a specific emoji.

What is a dark mode?

People who use their phones or computers late at night or in the dark often suffer from eye strain. This is because many popular websites, apps, and even device UIs use light colour schemes. There's been research to suggest that dark modes, which re-skin the look of a site, app, or UI so that they appear darker, are more beneficial to not only your health but also your device's battery.

As a result, the next version of Android is expected to come with a system-wide dark mode. Services like Twitter offer a dark mode you can enable. Even Apple allows users to adjust the blue light levels they seen on their devices. Now, Facebook is jumping on board and offering a dark mode.

AppleHow To Unlock Facebook Messengers Secret Dark Mode With An Emoji image 2

How to unlock Facebook Messenger's dark mode

It's simple. Just follow these steps:

  1. Open or start a new chat thread with someone (or yourself).
  2. Insert the crescent moon emoji into the text field and send it.
  3. Once you do, you'll see many moons appear in the chat window.
  4. You'll also see an alert, asking you to activate a new dark mode in settings.
  5. Either tap the alert or go to your profile page in the app to activate it.
  6. You'll see a new option to turn on dark mode.

Some Android users are reporting they need to close the app, reopen it, then press the moon emoji to get the option to switch to dark mode. If you're having trouble getting it to work, this might be an easy fix. As is restarting your phone and repeating that process - the classic turn it off and on again never fails. 

Who can try Facebook Messenger's dark mode?

We've enabled it on Facebook Messenger from an iPhone X and Pixel 2 XL.

Most of our friends and family have also enabled it via their iOS and Android devices, though one friend said they didn't see the feature, so it appears to still be rolling out globally to users.