If you have iMessage installed on your Mac, you will find that iMessage keeps track of the chat history on your Mac. This could be very useful when you need to check the chat history for information you need. However, you may want to delete iMessage chat history on Mac and other iOS devices, and get rid of the old conversations or just to free up some space.
Just follow the simple steps below to delete individual or multiple messages on MacBook Pro, MacBook Air, MacBook or iMac.
There's also another way to clear iMessage chat history in Mac OS. You can do this through the command line. Quit out of iMessage and open Terminal, at the prompt type the following:
When all these are done, just relaunch iMessages on your Mac computer and you will find that the chat history on iMessage is empty now.
Besides your Mac, you might also use iMessage on iPhone, iPad and iPod. And to delete iMessage chat history on iPhone, iPad and iPod touch is different from that on Mac OS X. As a result, we'll describe how to permanently delete iMessages on iOS 11/10/9 devices.
Hold your finger down on the message until you get a popup menu.
With all the iMessages deleted/removed from your Mac and iPhone, your device must run faster. If your iPhone is slow after update, you can use iOS speedup tool -Tenorshare iCareFone to delete junk files and app cache to speed up your iPhone perofrmance.