Computers, Laptops & Tablets Apple How to Easily Share Your Mac's Screen Messages and iChat have screen sharing capabilities By Tom Nelson Writer Tom Nelson is an engineer, programmer, network manager, and computer network and systems designer who has written for Other World Computing,and others. our editorial process Facebook Twitter Tom Nelson Updated March 30, 2020 KTSDESIGN / Getty Images Apple Macs iPad Tweet Share Email Messages and the earlier iChat messaging client that Messages replaced have a unique feature that allows you to share your Mac desktop with a Messages or iChat friend. Screen sharing lets you show off your desktop or ask your friend for help with a problem you may be having. If you allow it, you can also let your friend take control of your Mac, which is helpful if your friend is showing you how to use an app or helping you troubleshoot a problem. The information in this article applies to Messages on Macs running macOS Catalina (10.15) through OS X Mountain Lion (10.8) and to iChat on Macs running OS X Lion (10.7) or earlier. Apple replaced iChat with Messages in July 2012. Co-operative screen sharing is a great way to troubleshoot issues 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. 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 both 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. Launch Messages, located in the Applications folder. It may also be present in the Dock. Initiate a conversation with your friend or select a conversation already in progress. 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. In the selected conversation, click the Details button in the top right of the conversation window. From the pop-up window that opens, click the Screen Sharing button. It looks like two small displays. A second pop-up menu appears. Choose to Invite to Share My Screen or Ask to Share Screen. Screen sharing with Messages allows you to easily contact to other Mac desktops. Lifewire 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 then accepts or denies the request. If the friend accepts the request, screen sharing starts. 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 ScreenSharing window. You'll see a notice that control has been requested. Accept or deny the request. Either party can end the screen sharing by clicking the flashing double display icon in the menu bar and then selecting End Screen Sharing from the drop-down menu. 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. Launch iChat. In the iChat list window, select one of your buddies. You don't need to have a chat in progress, but the buddy must be online, and you must select the person in the iChat list window. Select Buddies > Share My Screen With [your buddy's name]. A screen sharing status window opens on your Mac saying "Waiting for response from [your buddy].", When your buddy accepts the request to share your screen, you see a banner on your desktop that says "Screen Sharing with [buddy's name]." After a few seconds, the banner disappears, and your friend starts viewing your desktop remotely. 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. Select Buddies > End Screen Sharing to end the screen sharing session. View a Buddy's Screen Using iChat To request the opportunity to share someone else's screen: Launch iChat. In the iChat list window, select one of your buddies. You don't need to have a chat in progress, but the buddy must be online, and you must select him or her in the iChat list window. Select Buddies > Ask to Share [your buddy's name] Screen. A request is sent to your buddy asking for permission to share his or her screen. If the person accepts your request, your desktop shrinks to a thumbnail view, and your buddy's desktop opens in a large central window. Work in your buddy's desktop just like it was your own Mac. Your buddy sees everything you do, including seeing the mouse moving around the screen. Likewise, you see anything your buddy does. You can even get in a tug of war over the shared mouse pointer. Switch between the two desktops, your buddy's and your own, by clicking in the window for whichever desktop where you want to work. You can also drag and drop files between the two desktops. Quit viewing your buddy's desktop by switching to your own desktop, then selecting Buddies > End Screen Sharing. You can also click the Close button on the thumbnail view of your buddy's desktop.