How to Connect Your Mac to an External Monitor

The basic connection: cables and ports

Your Mac connects to a monitor through a single cable that carries both video and sometimes power. Which cable you need depends on two things: what port your Mac has, and what port your monitor has. The most common setup today is a USB-C or Thunderbolt cable on the Mac end and HDMI or DisplayPort on the monitor end — but older Macs use different ports entirely, so checking both devices first saves you from buying the wrong adapter.

Start by looking at the ports on the side or back of your Mac. If you see small oval ports that look like a sideways "U", those are Thunderbolt or USB-C ports — they look identical to the naked eye, but Thunderbolt ports are faster. If your Mac is older, you might see a larger rectangular port (Mini DisplayPort) or an older connector. On the monitor side, look for HDMI (a flat rectangular port), DisplayPort (a smaller rectangular port with a notch), or USB-C. Write down what you see, because this determines what cable or adapter you need to buy.

Key Takeaways

Check the ports on both your Mac and monitor before buying a cable — the connection type depends on what each device has.
Most modern Macs use USB-C or Thunderbolt ports, while most monitors use HDMI or DisplayPort.
If the ports don't match, you need an adapter that converts from your Mac's port to your monitor's port.
Once connected, your Mac usually recognizes the monitor automatically and displays on both screens unless you change the settings.
If nothing appears on the monitor after connecting, restart your Mac and check that the monitor is powered on and set to the correct input.

Finding the right cable or adapter

If your Mac and monitor have matching ports — for example, both have USB-C — you can use a standard cable designed for that connection. USB-C to USB-C cables are inexpensive and widely available. If the ports don't match, you need an adapter that converts one type to the other.

The most common mismatch is a Mac with USB-C or Thunderbolt connecting to a monitor with HDMI. In this case, buy a USB-C to HDMI adapter (sometimes called a converter). These are sold at electronics retailers and online for $15 to $40. Plug the USB-C end into your Mac and the HDMI end into the monitor. Some adapters also charge your Mac at the same time, which is useful if your Mac's battery is low.

If your Mac is older and has a Mini DisplayPort, look for a Mini DisplayPort to HDMI adapter or a Mini DisplayPort to DisplayPort adapter, depending on what your monitor accepts. Thunderbolt ports can use Thunderbolt cables or adapters, but they are more expensive than USB-C adapters — only buy a Thunderbolt cable if your monitor specifically requires it.

Plugging in and powering on

Connect the cable or adapter to your Mac first, then to the monitor. Turn on the monitor and make sure it is set to the correct input — most monitors have an input button on the front or back that cycles through HDMI 1, HDMI 2, DisplayPort, and other options. If you are not sure which input to use, try each one until you see your Mac's desktop appear on the monitor screen.

Your Mac should recognize the monitor within a few seconds. You will see the Apple menu appear in the top-left corner of the monitor, and your cursor will move to the new screen. If nothing appears after 30 seconds, disconnect the cable, wait 10 seconds, and reconnect it. Then restart your Mac by clicking the Apple menu, selecting Restart, and waiting for it to boot up again.

Arranging your displays

Once your monitor is connected and showing your Mac's desktop, you can control how the two screens work together. Open System Settings by clicking the Apple menu and selecting System Settings. Click Displays in the left sidebar. You will see thumbnails of both your Mac's built-in screen and your external monitor.

By default, your Mac treats the external monitor as an extension of your screen — you can drag windows from one to the other, and your cursor moves between them. If you want the external monitor to mirror your Mac's screen instead (showing the exact same thing on both), click the Displays settings and look for an option that says Mirror Displays or Arrangement. The exact wording varies by Mac model and operating system version.

You can also adjust the resolution and refresh rate of your external monitor in the same Displays settings. If text looks blurry or the screen flickers, try changing the resolution to match what your monitor is designed for — most monitors work best at their native resolution, which is usually listed in the monitor's manual or on the manufacturer's website.

Troubleshooting when the monitor stays blank

If you have connected everything but the monitor still shows no picture, start with the simplest fixes. Make sure the monitor is powered on — look for a light on the front or back of the monitor. Make sure the cable is fully inserted into both the Mac and the monitor; a loose connection is the most common reason for a blank screen. Check that the monitor is set to the correct input by pressing the input button and cycling through the options.

If the monitor still shows nothing, try a different cable or adapter if you have one available. Some cables fail or are defective, and testing with a different one tells you whether the problem is the cable or the Mac itself. If a different cable works, the original cable is faulty and should be replaced.

If the monitor remains blank with multiple cables, restart your Mac. Hold the power button for 10 seconds until the screen goes black, wait 30 seconds, then press the power button again to turn it back on. During startup, your Mac checks for connected displays and may recognize the monitor for the first time. If the monitor still does not show anything after a restart, the issue may be with your Mac's graphics hardware, and you should contact Apple Support or visit an Apple Store.

Using your external monitor as the main display

If you want your external monitor to be your primary screen — the one where new windows open and where the menu bar appears — you can change this in System Settings. Open System Settings, click Displays, and look for a section labeled Arrangement or Primary Display. Click on the thumbnail of the external monitor and look for an option to make it the main display. On some Macs, you drag the white menu bar from one display thumbnail to the other.

This is useful if you are using your Mac with a larger external monitor most of the time and only occasionally use the built-in screen. Once you set the external monitor as primary, it will remember that setting even after you disconnect and reconnect the monitor, as long as you use the same cable or adapter.

Disconnecting safely

You can disconnect your external monitor at any time without damaging your Mac or the monitor. straightforward unplug the cable from either end. Your Mac will recognize that the monitor is gone and move any windows that were on the external screen back to your Mac's built-in display. If you have set the external monitor as your primary display, your Mac will switch back to using the built-in screen as primary once the external monitor is disconnected.

If you plan to disconnect and reconnect the same monitor regularly, you may want to leave the cable connected to the monitor and only unplug it from your Mac. This reduces wear on both connectors and makes reconnection faster.

Frequently Asked Questions

Can I connect more than one external monitor to my Mac?

Yes, but the number of monitors depends on your Mac model. Most modern Macs support two external displays in addition to the built-in screen. Older Macs may support only one. Check your Mac's technical specifications on Apple's website to confirm how many external monitors your model allows. You connect each monitor using the same process — one cable per monitor.

Why does my monitor show a picture but the colors look wrong?

This usually means the monitor's color settings do not match your Mac's output. Open System Settings, click Displays, and look for a Color Profile option. Try selecting a different profile, such as sRGB or the monitor's native profile if available. If the monitor came with a disc or manual, it may include a color profile file that you can install. Restarting the monitor by turning it off and back on also sometimes fixes color issues.

Do I need to buy an expensive cable, or will any USB-C to HDMI adapter work?

Any USB-C to HDMI adapter that is rated for your Mac's power output will work. You do not need to buy the most expensive option. Look for adapters with good reviews that mention your Mac model, and make sure the adapter supports the resolution you want — most support at least 1080p, and many support 4K. Budget adapters work fine for most people.

What if my Mac is very old and I cannot find an adapter for its port?

Older Macs with Mini DisplayPort or Thunderbolt ports can still connect to modern monitors, but you may need to search specifically for adapters designed for that older port type. Retailers like Amazon and B&H Photo carry adapters for older Macs. If you cannot find an adapter, contact Apple Support with your Mac's model and year — they can tell you what connection options are available for your specific machine.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.