Why the connector matters
A video cable carries the picture from your computer to your screen. Many shapes are in use, and they are not all interchangeable. The connector decides whether the cable physically fits, and the standard behind it often decides the highest resolution and refresh rate the connection can carry. A cable that fits is not necessarily a cable that will deliver the picture you hoped for.
The common connectors
You are likely to meet a handful of types. Descriptions here are general, so confirm details in your device manuals.
- HDMI. Common on monitors, televisions, game consoles and many laptops. It carries both picture and sound in the same cable. It comes in several versions, and newer versions generally support higher resolutions and faster refresh rates. It also comes in full-size, smaller and smallest connector shapes.
- DisplayPort. Common on monitors and desktop graphics cards, and often favored for higher refresh rates and high resolutions. Its full-size plug usually has one angled corner and often a small latch. A smaller variant, sometimes called Mini DisplayPort, also exists.
- DVI. An older digital connector, wide and rectangular with many pins and thumbscrews. It still appears on older monitors and graphics cards. Some versions carry analog signals as well as digital ones.
- VGA. An older analog connector with a blue, trapezoid-shaped plug and three rows of pins. It is limited in sharpness and can show fuzzy text, ghosting or slight wobble on modern screens, though it is useful for older equipment.
- USB-C. A small, reversible plug. Many laptops and some monitors can send video through it, but not every USB-C port does. A port may only handle data and charging, so look for a display symbol or check the manual.
If you are trying to understand USB-C in the wider sense, see the article on USB ports, which covers the data side of these connections.
Digital versus analog
Digital connections such as HDMI, DisplayPort and DVI-D send the picture as data, which usually leads to a clean, sharp image at the screen’s native size. Analog connections such as VGA send a varying electrical signal that must be converted, which can soften the image. When you have a choice, use a digital connection.
Matching a cable to both ends
The simplest approach is to make a short list.
- Look at the video outputs on the computer or graphics card.
- Look at the video inputs on the monitor.
- Find a connector type that appears on both lists.
- Buy or use a cable with that same connector at each end.
If there is no shared type, you need an adapter or a cable with different connectors at each end, such as one with HDMI on one side and DisplayPort on the other. Read the product description carefully: some adapters only work in one direction. A cable that converts from computer output to monitor input does not necessarily work in reverse, and some conversions between digital and analog require powered converters.
Where to plug in on a desktop
On a desktop with a separate graphics card, there are often video ports on both the card and the motherboard. In most setups you should plug the monitor into the graphics card, because the motherboard ports usually connect to built-in graphics and may be disabled when a card is installed. If you get no picture after installing a new card, this is one of the first things to check. Our article on graphics hardware explains the difference between built-in and separate graphics.
Cable versions and quality
Not all cables with the same plug perform the same. Older or very cheap cables may not carry a high-resolution or high-refresh-rate signal reliably. Long runs can make the problem worse. Signs of a marginal cable include a picture that drops out, flashes, shows sparkles or noise, or will only run at a lower setting than the monitor claims.
When picking a cable:
- Check which version or rating it claims to support and whether it matches your monitor’s capabilities.
- Prefer a shorter cable if a short one reaches comfortably.
- If a problem appears, try another cable before blaming the screen.
Take care with marketing language that promises more than the ports can deliver. The weakest link, whether port, cable or adapter, sets the limit.
Sound over video cables
HDMI and DisplayPort can both carry audio, but the monitor needs to pass it on, through speakers or a headphone jack. If you get no sound, check the computer’s output device selection and the monitor’s menu rather than assuming the cable is faulty. The general troubleshooting for this appears in display problems, which covers common fixes when there is no sound or no picture.
Connecting safely
If you have several connections behind the desk, label the cable ends and keep them tidy with some basic cable management so that you can tell which lead goes to which screen. This is especially useful if you are building a setup with multiple monitors.
If there is no picture
- Confirm the monitor is on and set to the right input source in its own menu. Many monitors do not switch inputs automatically.
- Reseat both ends of the cable.
- Try another port or another cable.
- Check that the computer is not sending the picture to a different screen.
- Restart the computer.
If these steps do not help, test the monitor with another device to find out whether the fault is with the screen, the cable or the computer.