How to Share a Mac Screen

Whether you need tech support from afar or you'd just like to see your Mac's screen mirrored (but bigger), screen-sharing is the best way to get your results! There are numerous ways for you to share the contents of your Mac's screen, from...

Method 1 of 4:

Using AirPlay

Make sure you have the proper equipment. In order to mirror your computer's display on a TV, you'll need a computer running OS X 10.8 (Mountain Lion) or later and at least a second-generation Apple TV.^[1]
1. If you don't have the proper equipment, you can still view your computer's screen on your TV with an HDMI cable!
Turn on your TV, then turn on your Mac. Wait for your TV to fully boot up before attempting to connect your Mac.
Click on the AirPlay icon. This is in your menu bar in the top-right corner of your Mac's screen; it resembles a rectangular outline with a triangle at the bottom.
Click the "Apple TV" option at the bottom of the menu. If you have several Apple TVs on the same network, you'll need to select the one to which you wish to connect from a drop-down menu.
Click the "Extended Desktop" option when prompted. This will display your desktop on the Apple TV, thereby allowing you to watch YouTube videos or stream online media from your laptop to your TV.
Adjust your TV preferences. If this is your first time connecting your Mac to your Apple TV, the TV's resolution might appear inadequate; this is because your Apple TV applies picture-quality enhancements to on-screen images by default, which can distort computer images. To fix this, you'll need to consult your TV's manual.
1. For most TVs, setting the display filter to "Standard" or "Normal" (or "Computer" if your TV has it). Avoid settings such as "Cinematic", "Dynamic", or "Gaming".

Method 2 of 4:

Using an HDMI Cable

Make sure you have an HDMI cable and a capable TV. An HDMI cable is a high-definition connector that allows you to hook devices such as computers, consoles, and receivers up to your TV. If you don't have an HDMI cable, you can buy a high-quality one from most technology stores or Amazon for under $20.
1. If you have an HDTV, it probably has an HDMI input.
2. Your Mac should have an HDMI port on the right side; if you have a recent model of Mac, it should say "HDMI" next to the port.
Plug one end of your HDMI cable into your Mac's port. Make sure the cable is facing the right way--e.g., the smaller part of the cable end is on the bottom.
1. If your Mac doesn't have an HDMI cable, you'll need to purchase an adaptor. In this case, you'll need a "Thunderbolt to HDMI" adaptor to plug into the left side of your Mac.
Attach the other HDMI cable end to your TV. Your TV's HDMI slot will look like your computer's.
Make sure your TV's input is set to the proper channel. You'll have to set your TV's current channel to an input; if your TV has multiple HDMI outlets, you may have to cycle the TV's input to get the right one to display. Depending on your TV model, you can usually do this by tapping the "Input" button on either the remote control or on the display itself.
1. For example, if your chosen HDMI port is labeled "HDMI 2", you'll need to press your "Input" button until you see the phrase "HDMI 2" on your TV's screen.
Wait for your Mac's picture to display. This may take a few seconds; once the connection solidifies, your Mac's screen should show up on your TV!
Set up your TV's preferences. If you've never altered your TV's display filter, it may still be on "Dynamic" or "Cinematic" from the store. To achieve the highest-quality picture possible, your TV's display should be set to "Normal" or "Standard" (contingent on your TV model). Consult your TV's manual in order to complete this process.
1. Your TV may also have a "Computer" setting; if available, this setting is ideal for your purposes here.

Method 3 of 4:

Sharing and Viewing to a Computer (Wireless)

Open your Mac. If you want to share your screen with someone remotely, you'll first need to enable screen-sharing.
Click the Apple icon in the top left corner of your screen. This will open the Apple menu. You'll need to edit your sharing settings in order to fully enable your Mac's screen-sharing capabilities.
Click the "System Preferences" option. This will take you to your Mac's system preferences menu.
Click the "Sharing" option. This should be under the "Internet and Wireless" subheading.^[2]
Click the "Screen Sharing" box to check it. You'll find this option under the "Service" section on the left side of the Sharing menu.^[3]
1. By default, no other boxes should be checked.
2. If the "Remote Management" box is checked, you'll need to uncheck it in order to select the Screen Sharing option.
Check the "Only these users" box. This is next to the "Allow access for" box on the right side of the menu; doing so will afford access only to people with your Mac's IP address and administrator login information.^[4]
1. As a general rule, avoid allowing access to "All users"; doing so would be a security risk.
2. The default option here is the "Administrators" account.
Write down your Mac's IP address. You can find this above the access box and under the "Screen Sharing: On" text. You'll need to give your Mac's IP address to anyone you want viewing your shared screen.
Exit the System Preferences menu. You are now ready to share your Mac's screen!
Begin the screen-viewing process. To do this, you'll need another Mac capable of connecting to your Mac's network.
Open the Finder app. This is the blue face icon in your dock.
Click the "Go" tab. This should be at the top of your screen; clicking it prompts a drop-down menu.
Click the "Connect to Server" option. You'll find this at the bottom of the "Go" menu.
1. You can also hold down ⌘ Command and tap K to bring up the "Connect to Server" menu.
Type "vnc://[target Mac's IP address]" into the "Server Address" field. Exclude the quotation marks and brackets when doing so.
Type in the Mac's admin username and password. These should be the credentials used to log into your target Mac; if you don't have these credentials, contact the target Mac's user to obtain them.
Click "Connect" to connect to the sharing Mac. This may take a minute or so, depending on your wireless connection. You are now viewing a Mac's screen wirelessly!

Method 4 of 4:

Sharing Your Screen on Skype

Open Skype. If you'd like to share your desktop with a contact, you can do so from within a video call on Skype.
Click the Skype conversation you wish to open. To share your screen during a video call, you'll need to actively be in a call with a person or a group; you can initiate a call by clicking the video camera icon in the top-right corner of your conversation screen.
1. Your ongoing conversations and past conversations are saved on the left side of your screen.
Click the Share icon at the bottom of your conversation. This resembles a cloud with a "+" sign inside.^[5]
Click the "Share Screen" option.
1. You may have to disable your video projecting first. You can do this by clicking the video camera icon in the top-right corner of your screen.
Click the "Share your entire screen" option. This option will allow you to share an image of your screen, including your desktop and any actions you choose to take.
1. You can also click "Share your window" to share a specific frame from your Mac.
Click "Start" when prompted. This will begin sharing your screen.
Click the Share icon, then click "Stop Screen Sharing". This will end your current screen sharing when you're ready.