Can an HDMI Splitter Extend the Display to 2 Monitors?

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Dual monitors can significantly improve your computer’s viewing experience, but with only one HDMI port on your computer, how can you extend the display to an additional monitor? While there are several options you could look into, for many people, a splitter is the first thing they think of. Unfortunately, using a splitter can come with some issues.

An HDMI splitter can’t extend the display to two monitors. What a splitter does is mirror the original image to 2 or more displays. A USB-to-HDMI adapter may effectively add a second HDMI port, which will extend the display. However, not all computers are able to output to a display via a USB port.

A splitter may seem like the right tool to extend your display, but it’s not suitable for the job. Splitters do have their purpose, and if you are trying to duplicate the display, they are perfect. But, HDMI splitters are limited by specific legal protocols. This makes them incapable of truly splitting the signal.

Why You Can’t Use an HDMI Splitter to Extend the Display to 2 Monitors

Person holding an HDMI Splitter

A splitter does exactly what it advertises. It takes the HDMI signal and splits it into two or more of the same image. While this may not seem like a challenging task, it can come with some roadblocks. The first one being HDCP.

HDCP, or High-Bandwidth Digital Content Protection, is protection security that comes standard in most HDMI systems. This protection helps to keep media pirates from copying content via HDMI. Devices need to be HDCP certified for them to be able to pass the signal along. Because of this, any piece of your system that touches HDMI needs to be HDCP certified. 

Consequently, if they are not HDCP certified, you will either get a black screen or a message indicating the lack of certification. The problem that occurs with cheaper HDMI accessories is that they are not certified. The certification costs money, something that cheap producers are not willing to shell out. But, what they do is find a fix.

Some HDMI splitters can take advantage of an HDCP loophole, by bypassing the HDCP encryption with something known as a fallback. When the signal goes through the non-HDCP compliant splitter, it “falls back” to a lower resolution instead of showing a black screen. For example, a 1080p signal splits into two 720p mirrored screens.

To sum up, splitters do not extend the feed; they duplicate it. Most are not HDCP compliant, moreover, they’re usually cheaper and poorly designed products. One thing to look out for is the labeling on the device. If you see something like “1×2” or “1×4,” it is a good sign that you are looking at a splitter; this is a dead giveaway. While a splitter can’t extend an image, some products can.

How to Extend the Display to Two Monitors with 1 HDMI Port

Cable Matters SuperSpeed USB 3.0 to HDMI Adapter (USB to HDMI Adapter) for Windows up to 1440p in Black

To properly extend an image onto a second display, you need an adapter. This will transform one of your USB ports into an HDMI out which means you will need access to a USB port for everything to work. Because one HDMI port can’t extend your display, you’ll need an adapter to accomplish this task.

Fortunately, there are plenty of easy-to-use and reliable adapters on the market. Products like the Cable Matters USB-to-HDMI Adapter (on Amazon) are perfect for this type of issue. Adapters are easy to use and follow a simple plug-and-play setup. What this translates to is a simple solution to your problem.

There are also other types of adapters that work with different ports including the USB-to-VGA, Thunderbolt to HDMI, as well as adapters that use USB 3.0. Furthermore, if USB ports are at a premium, you could always purchase a USB hub.

These will effectively allow you to use multiple adapters to power multiple displays. Hubs like this one (on Amazon) are easy to use, more importantly, the USB hub is crucial if you intend to keep your dual displays. This is because it will put a port out of use. Keeping this in mind will help you manage your ports and not run into any issues down the road. 

Extending the Display with a USB-Dock

If you plan to make your dual displays permanent, you may want to purchase a USB dock. These devices often stay stationary and handle multiple types of connections and ports. For example, a USB dock will feature more USB ports, a 3.5 mm Audio Out, Display Ports, USB-C ports, and a few other things.

While a one-off adapter may solve the problem, a dock will serve as a more suitable solution. This is because they are standalone products that can reliably extend the ports and displays. They add the necessary HDMI out and come with a convenient array of other ports.

It is also a more suitable solution if your system is relatively stationary. A USB hub can sit on your desk and be used with a laptop when needed or attached to a desktop unit. A couple of great options for the Mac and PC are the Lention USB-C Multi-Port Hub (on Amazon) as well as the Plugable USB 3.0 Docking Station (on Amazon).

It is worth noting that most USB hubs can work on either a Mac or PC. What you should look out for is the type of USB. For example, newer Macbooks and Mac computers will feature only USB Type-C. In contrast, while you may still find USB-C on PC builds, you may also have a USB 3.0 port. There are also products, like the EUASOO Docking Station (on Amazon) that can support up to three HDMI outs. This means you can have triple monitors that can extend your display.

Wrapping Up

If you want to extend your image and use dual displays, a splitter just won’t work. A splitter can split the image into two duplicates but can never extend the image. To do this, you need an adapter. But, if you are looking for a stationary solution, maybe a USB docking station with access to multiple ports is a better option.

With the right hardware, you can easily set up your monitors exactly the way you want them. Just a little understanding of what all these technologies do can really help when it comes time to purchase hardware.

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