If you are too busy to chat with your friends or simply don’t want to be bombarded with messages when you go online on your mobile, this guide will teach you how to change your online status on Facebook Messenger to appear offline.
For iPhone
To appear offline using an iPhone, open the Facebook Messenger app and select your address book. Tap on the Active tab, and toggle the switch displayed next to your username to the Off position.
Once you have successfully disabled Facebook Chat your mobile, you will no longer appear in your friends’ Active tabs.
For Android
To appear offline on Facebook Messenger using Android, open the app, then click your profile picture in the top-right corner of the screen. Next, go to Active Status
There, you will see the Show when you’re active option. To appear offline, you need to turn deactivate this setting. To confirm your changes, select Turn off in the dialog box that appears
N.B. After deactivating your online status, you won’t be able to see when your contacts are active or have been recently active on Facebook Messenger.
Source: CCM