Co-operative screen sharing is a great way to troubleshoot problems with a friend. It also provides a unique way for you to teach others how to use a Mac application. When you’re sharing someone’s screen, it’s just like you’re sitting down at that person’s computer. You can take control and work with files, folders, and applications—anything that is available on the shared Mac’s system. You can also allow someone to share your screen.
Set Up Screen Sharing
Before you can ask someone to share your Mac’s screen, you must first set up Mac screen sharing in the Mac’s System Preferences Sharing section. After you enable screen sharing, you can use Messages or iChat to allow others to view your Mac or for you to view someone else’s Mac.
Why Use Messages or iChat for Screen Sharing?
Neither Messages nor iChat performs screen sharing. Instead, the process uses the built-in VNC (Virtual Network Computing) clients and servers in your Mac. So, why use messaging apps to initiate screen sharing? By using the messaging apps, you can share your Mac’s screen over the internet. Even better, you don’t have to configure port forwarding, firewalls, or your router. If you can use Messages or iChat with your remote buddy, then screen sharing should work as long as there’s a fast enough network connection between the two of you. Messages or iChat-based screen sharing can’t be easily used for remote access to your own Mac since the messaging apps assume that there’s someone present at both machines to initiate and accept the screen sharing process. If you attempt to use Messages or iChat to log into your Mac while you’re on the road, there won’t be anyone at your Mac to accept the request to connect. So, save the messaging apps for screen sharing between you and another individual. You can use other screen sharing methods when you want to connect to your own Mac remotely.
Screen Sharing Using Messages
If you run macOS Catalina (10.15) or earlier through OS X Mountain (10.8), you have the Messages app on your Mac.
Share Your Mac’s Screen With an iChat Buddy
If you run OS X Lion (10.7) or earlier on your Mac, you have iChat instead of Messages. Messages makes use of your Apple ID and iCloud to initiate the screen sharing process, so screen sharing with Messages doesn’t work for Bonjour or other Messages account types, only with Apple ID accounts. A notice is sent to the friend, informing them that they have either been invited to view your screen or that you’re asking to view their screen. The friend viewing your Mac’s desktop can only initially view the desktop, and won’t be able to interact directly with your Mac. They can, however, request the ability to control your Mac by selecting the Control option in the Screen Sharing window.
View a Buddy’s Screen Using iChat
To request the opportunity to share someone else’s screen: A screen sharing status window opens on your Mac saying “Waiting for response from [your buddy].” When someone shares your desktop, they have the same access rights as you do. They can copy, move, and delete files, launch or quit applications, and change system preferences. You should only share your screen with someone you trust. A request is sent to your buddy asking for permission to share his or her screen.
