What you'll need
To connect a monitor to a laptop, plug a cable from a laptop port that carries video (HDMI, or a USB-C or Thunderbolt port that supports DisplayPort Alt Mode) into the matching input on the monitor, switch the monitor to that input, then extend your desktop: press Windows+P and choose Extend on Windows, or open System Settings > Displays on a Mac. If the laptop lacks native video output, investigate a supported USB graphics adapter with its required driver; an ordinary dock cannot add a missing native signal. For two monitors, verify the exact laptop, OS and dock combination.
Step 1: Find a laptop port that carries video
Check the laptop’s spec sheet or the icons beside its ports.
| Laptop port | Carries video? | What to look for |
|---|---|---|
| HDMI | Yes | The simplest option for one monitor or a TV |
| USB-C | Only some ports | A DisplayPort (D) or Thunderbolt (lightning) icon, or “DisplayPort Alt Mode” in the specs |
| Thunderbolt 3/4/5 or USB4 | Yes | Can also carry power and data on the same cable |
| DisplayPort or Mini DisplayPort | Yes | Less common on current laptops |
| USB-A | No (native) | Needs a DisplayLink adapter or dock with its driver installed |
A USB-C port that only charges or moves data will not send a picture, and a passive video adapter cannot add a missing native signal. Driver-based USB graphics is a separate route with OS and installation requirements.
Step 2: Pick the cable that matches both ends
- HDMI to HDMI if both have HDMI.
- USB-C to USB-C if the monitor has a USB-C input with video; this can also charge the laptop if the monitor supplies USB Power Delivery. Our USB-C monitor guide explains what to check.
- USB-C to HDMI or USB-C to DisplayPort cable if the laptop has video-capable USB-C and the monitor has only HDMI or DisplayPort.
- A dock if you need charging, Ethernet and USB ports on one cable, or two external monitors. Use the USB-C connection worksheet to check the required video and power path.
One direct cable is more reliable than a chain of adapters, because each extra link is another place for a blank screen or a sleep-wake glitch.
Step 3: Power the monitor and select the input
Turn the monitor on, then use its menu or input button to select the port you plugged into (HDMI 1, HDMI 2, DisplayPort or USB-C). Confirm the input before changing drivers or buying a cable.
Step 4: Turn on the second screen in the operating system
Windows 10 and 11: press Windows+P and choose Extend to use the monitor as a second screen, or Duplicate to mirror the laptop. Then open Settings > System > Display, drag the screens to match where they sit on your desk, and select Apply. Microsoft documents these steps in How to use multiple monitors in Windows .
Mac: Apple says the Mac detects a powered, connected display automatically; you then arrange it in System Settings > Displays (Connect displays to your Mac ). How many external displays a Mac can run depends on its chip; base M1 and M2 MacBook Air models support one. Check Apple’s MacBook Air display support for your exact generation.
If the monitor shows no signal
- Confirm the monitor input matches the port you used.
- Try a different cable, or plug directly into the laptop instead of through an adapter.
- Check that the laptop’s USB-C port supports video (Step 1).
- On Windows, press Windows+P and make sure Extend or Duplicate is selected. Microsoft’s external monitor troubleshooting page covers driver and detection fixes.
- On a Mac, hold Option in Displays settings to show Detect Displays, as described in Apple’s external display guide .
Connecting two monitors to a laptop
A laptop needs either two video outputs or one Thunderbolt/USB-C port plus a dock that splits the signal. Windows laptops and Chromebooks can use MST docks such as the Plugable UD-MSTH2 ; base M1/M2 MacBook Air and 13-inch MacBook Pro models need a supported software-display route, such as a DisplayLink dock such as the Plugable UD-6950PDH to get past their one-display limit. The Pro/Max variants and desktop Macs have different native limits. Read Apple’s exact model specification before buying a dock.
No room for a desk monitor?
A compatible portable monitor can provide a compact second workspace, but video and adequate power must both be available. Use the portable-screen packing and connection guide before assuming one cable or a particular bag will work.