How to Connect a Monitor to Your Computer

The cables and ports you need to know

Most monitors connect to your computer through one of four cable types: HDMI, DisplayPort, USB-C, or VGA. HDMI is the most common — it carries both picture and sound through a single cable and works with almost every device made in the last ten years. DisplayPort is faster and often found on gaming monitors and newer laptops. USB-C can do video, power, and data all at once, which is why newer laptops and monitors increasingly use it. VGA is the older standard with a blue connector and three rows of pins; it still works but only carries picture, not sound.

Your monitor has at least one of these ports on the back. Your computer — whether desktop, laptop, or tablet — has at least one as well. The cable you need depends on which ports both devices have. If your monitor has HDMI and your computer has HDMI, you use an HDMI cable. If one device has DisplayPort and the other has HDMI, you need an adapter or a cable with different ends.

Check what ports your monitor has before you buy it. Look at the back panel or the manual. Do the same for your computer. If they do not match, you will need an adapter, which costs between $10 and $30 depending on the type.

Key Takeaways

HDMI is the most common monitor cable and works with nearly all computers made in the last decade.
If your monitor and computer ports do not match, you will need an adapter — check both devices before you buy.
USB-C monitors can charge your laptop at the same time they display video, which saves desk space and cables.
Once connected, your computer may need you to choose which monitor to use or adjust the display settings in your system preferences.
If the picture does not appear, restart both the monitor and the computer, then check that the cable is fully seated in both ports.

Connecting an HDMI monitor to a desktop or laptop

Locate the HDMI port on the back or side of your monitor. It is a flat rectangular port about the size of a USB port, but wider. Locate the HDMI port on your computer — on a desktop this is usually on the back of the tower, and on a laptop it is on the side. Plug one end of the HDMI cable into the monitor and the other end into the computer.

Turn on the monitor first, then turn on the computer. The picture should appear within a few seconds. If it does not, try unplugging the cable from both ends and plugging it back in firmly — a loose connection is the most common reason a monitor does not show a picture.

On Windows, right-click on the desktop and select "Display settings" to adjust the resolution or orientation. On Mac, go to System Preferences, then Displays, to make the same changes. Most computers detect a new monitor automatically and set it to the best resolution for that screen.

Using USB-C for video and power at once

USB-C monitors are becoming common on newer laptops because they can send video, power, and data through a single cable. This means you plug in one cable and your laptop charges while you use the monitor. This saves space on your desk and reduces cable clutter.

To connect a USB-C monitor, plug the USB-C cable into the USB-C port on your monitor and into the USB-C port on your laptop. The monitor should power on and detect your laptop within a few seconds. Your laptop may also begin charging when ready — check the battery icon in your system tray to confirm.

USB-C monitors work with Windows laptops, Macs, iPads, and some Android tablets, as long as the device has a USB-C port. If your laptop has USB-C but your monitor does not, you can buy a USB-C to HDMI adapter and still use the monitor, though you will lose the charging feature.

Connecting when your ports do not match

If your monitor has HDMI but your computer only has DisplayPort, or vice versa, you need an adapter. These are small devices that convert one cable type to another. A DisplayPort-to-HDMI adapter costs $15 to $25 and works in either direction — you can plug DisplayPort into one end and HDMI into the other.

For older computers with only VGA ports and newer monitors with only HDMI or DisplayPort, you can buy a VGA-to-HDMI adapter, though the picture quality may be lower because VGA is an older standard. If your computer has USB-C and your monitor has only HDMI, a USB-C-to-HDMI adapter works the same way.

Buy the adapter before you buy the monitor if you are unsure about compatibility. Most electronics retailers and online stores accept returns within 30 days, so you can test the setup and return the adapter if it does not work.

What to do if the picture does not appear

Start by checking the cable. Unplug it from both the monitor and the computer, wait five seconds, and plug it back in firmly. Make sure the cable is pushed all the way in — a partially seated connector is the most common reason a monitor stays blank.

Restart the monitor by turning it off and back on. Then restart the computer. Wait 30 seconds after each restart before checking for a picture. If you still see nothing, try a different cable if you have one available, or borrow one from a friend to rule out a bad cable.

On a laptop, you may need to press a key combination to send video to the external monitor. On Windows, try pressing Windows key + P to open the display menu and select "Extend" or "Duplicate". On Mac, hold down the Option key and click the AirPlay icon in the menu bar, then select your monitor. If your computer has a dedicated display button (often with a monitor icon), press that as well.

Setting up multiple monitors

If you want to connect two or more monitors to one computer, check how many video ports your computer has. Most desktops have at least two ports (often one HDMI and one DisplayPort). Most laptops have only one, though you can add more using a docking station or USB adapter.

Connect each monitor to a different port on your computer using the appropriate cables or adapters. Turn on all the monitors, then turn on the computer. Windows and Mac will detect all the monitors and let you arrange them in your display settings.

In Windows, go to Settings > System > Display and scroll down to "Multiple displays". You can choose to extend your desktop across all monitors, duplicate the same image on each one, or use only one monitor. On Mac, go to System Preferences > Displays and click "Arrangement" to drag the monitor icons into the layout that matches your physical setup.

Troubleshooting sound from your monitor

HDMI and USB-C cables can carry sound as well as video, but your computer must be set to send audio through the monitor. On Windows, right-click the volume icon in the system tray, select "Open Volume mixer", and look for your monitor in the list of output devices. Click on it to make it the default. On Mac, go to System Preferences > Sound > Output and select your monitor from the list.

If your monitor has built-in speakers but you do not hear sound, check that the monitor's volume is not muted. Most monitors have a menu button on the back or side; press it and look for a volume or audio setting. Also confirm that your computer is not muted — check the volume icon in your system tray or menu bar.

If your monitor has no speakers or you prefer external speakers, you can connect a separate speaker or headphone set to your computer's audio jack or USB port. This does not affect the video connection at all.

Frequently Asked Questions

Can I use an HDMI cable longer than 25 feet?

HDMI cables work reliably up to about 25 feet. Beyond that, the signal can degrade and you may see a black screen or flickering picture. If you need to run a cable farther than 25 feet, use an HDMI extender or repeater, which costs $30 to $50 and boosts the signal so it travels farther without loss.

Do I need to turn off my computer before plugging in a monitor?

No. Modern computers and monitors are designed to handle hot-plugging — connecting or disconnecting cables while powered on. However, restarting both devices after connecting a new monitor often helps the computer detect it faster and set the correct resolution.

What if my monitor cable keeps coming loose?

HDMI and DisplayPort connectors have small clips that hold them in place. Make sure the clip is fully engaged by pushing the cable in until you hear or feel a click. If the port itself is loose or damaged, the monitor may need repair. If the cable connector is damaged, replace the cable.

Can I connect a monitor to a tablet or phone?

Yes, if your tablet or phone has USB-C or a video output port. iPads with USB-C can connect to USB-C monitors or HDMI monitors with an adapter. Some Android tablets have USB-C or HDMI ports as well. Most phones cannot drive an external monitor, though some high-end Android phones support it through USB-C.

Is DisplayPort better than HDMI for gaming?

DisplayPort supports higher refresh rates and resolutions than HDMI, which matters for competitive gaming where fast response time is important. If you play games and your monitor and graphics card both support DisplayPort, it is the better choice. For everyday use, HDMI and DisplayPort perform the same.

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.