Are you looking for a way to extend your display to two or more monitors? Many laptops only have one HDMI output port, which allows you to connect to one external display. But what if you want to connect multiple displays to one device?
At first look, it doesn’t seem possible. However, there are certain devices you can use to successfully extend your display to two or more monitors.
Having the extra screen real estate that extended monitors provide can boost your productivity and workflow.
Let’s take a look at your options.
Can an HDMI Splitter Extend the Display to 2 Monitors?
No. You cannot extend your display with an HDMI splitter because an HDMI splitter simply duplicates the signal. To extend your display, an HDMI adapter is required. An HDMI adapter such as this USB 3.0 to HDMI adapter can extend your laptop’s display to two monitors.
What Does an HDMI Splitter Do?
An HDMI splitter is a small device with one male HDMI and two or more female HDMI ports. The HDMI splitter takes a video source and sends it to multiple HDMI outputs.
In practical terms, to show the same media on multiple displays, an HDMI splitter is what you need. It’s useful for presentations and whatnot. Just remember, an HDMI splitter will not extend your display, it will only show the same image on every connected screen.
Many laptops nowadays don’t even have HDMI output. How can you connect a laptop that does not have HDMI to two or more monitors?
There are a few ways to accomplish this goal, although the steps required will depend on the ports available on your computer.
Extend Display With Only 1 HDMI Port
If your laptop only has one HDMI port, you can still connect multiple monitors to use extended mode. One monitor would be connected to the HDMI port on your laptop and the other either via USB 3.0 to HDMI or USB-C to HDMI.
Your computer should automatically detect the new displays and allow you to enable extended mode.
Easy!
Extend Display With No HDMI Ports
Use a USB 3.0 to 2 x HDMI Adapter
When your laptop or computer has no HDMI ports, the easiest option is to buy a StarTech USB 3.0 to HDMI display adapter.
These dongles appear similar to HDMI splitters, but one end is USB and not HDMI. A USB 3.0 to HDMI display adapter can extend your desktop to two additional or more displays.
In fact, you can continue using your laptop’s screen as a third or middle display, thus adding even more screen real estate to your setup.
How it Works
- Connect the USB end of the adapter to a USB 3.0 port on your computer or laptop
- Connect your displays to the HDMI ports on the adapter
- Download and install any necessary drivers (the instructions should include a link to the files)
- Your computer should detect the displays and automatically switch to extended desktop mode
- You can use the Window’s Manage Displays feature to adjust the displays (or hit Windows + P)
Bear in mind, that USB 3.0 has a much lower bandwidth than other types of connectors, so these adapters do not support 4K at 60 Hz.
Extend Display with only USB-C or Thunderbolt
Use a USB-C to 2 x HDMI
Today most laptops have at least one USB-C or Thunderbolt port. With this USB-C to 2 x HDMI dongle, you can use a single USB-C port to connect two monitors in extended desktop mode. No external power or drivers are required, it’s all plug and play.
To set up, attach the USB-C end to a USB-C port on your laptop, and then attach your displays’ HDMI cables to the HDMI ports. Your computer should automatically detect the monitors as individual displays.
Bear in mind, that this specific dongle will not work on MacBook or other Mac OS devices. It’s only compatible with Windows at the moment.
Extend Display with Only DisplayPort
DisplayPort to HDMI
So you have a computer that has DisplayPort and you want to connect it to multiple displays. There are a few options.
Since you have one DisplayPort on your computer, you can use that for one monitor, and then connect the second using a USB 3.0 to HDMI adapter.
Another option would be to buy a DisplayPort to 2 x HDMI splitter, make sure the one you choose supports extended mode.
I like the G2G DisplayPort to Dual HDMI dongle. Bear in mind, that this specific adapter requires an additional power source via a Micro USB cable.
Extending Monitors on Mac
Using multiple monitors in extended mode on Mac is tricky because there are limitations for each device. For example, the Mac Mini can natively support up to two external monitors, but MacBooks can only support one external monitor.
The new M1 MacBooks can also only natively support one external monitor. To make matters worse, the previously mentioned dongles won’t work with macOS either.
Use a DisplayLink Dell Docking Station
There is one workaround. What you need is a hub or dongle that supports DisplayLink. Dell makes a few of these hubs, and they’re a bit pricey, but so far it’s the best option out there.
I like the Dell D3100 docking station. I’ll walk you through how to set it up using a MacBook.
- Connect the D3100 docking station to a power source using the included adapter
- Connect your MacBook to the hub using the included USB-C to USB-B cable
- Attach your HDMI monitors to the HDMI slots on the hub
- Visit DisplayLink Downloads and download the latest drivers for macOS
- Once installed, your MacBook should detect the monitors, and you can use them in extended mode
The Dell docking stations also work on Windows devices. However, it’s much cheaper to use the adapters mentioned earlier for Windows.
Tips on Using HDMI Dongles
There are a couple of pointers to keep in mind when using a USB to HDMI display adapter.
For one, these adapters will not work with USB 2.0 because it does not support the speed bandwidth requirements. If you’re not sure which USB ports on your computer are USB 3.0 look for any that have a blue label.
While USB 3.0 supports much higher bandwidth than USB 2.0 it still does not support enough for two 4K monitors at 60 Hz. These USB video adapters are limited to 1080P at 60 Hz.
Finally, and this is important, USB video adapters usually only work with Windows because they require specific software.
Around 90% of USB display adapters only work on Windows. On that note, some also require additional drivers, so make sure to check the included instructions.
HDCP Copyright Protection
Some HDMI dongles do not have a proper HDCP (High Bandwidth Digital Content Protection) certificate, so you won’t be able to watch copyrighted media. HDCP is built-in to all HDMI cables and devices.
For example, if you try to watch Netflix on a monitor that’s connected to an HDMI dongle that does not support HDCP, it might lose the signal. In most cases, when using a USB to HDMI dongle or hub you don’t need to worry about HDCP issues.
Either way, it’s better not to get the cheapest dongle on the market. You want one that can deliver consistent quality without disconnecting at random times.
HDMI 2.1
HDMI 2.1 can be found on new TVs and it supports resolutions up to 8K or 4K at 120 Hz.
Certain laptops that have a Thunderbolt 4 port which supports DisplayPort Alt-Mode can also support the HDMI 2.1 features.
You could use a single USB-C to HDMI 2.1 adapter to connect an HDMI 2.1 display to your computer. If you have multiple Thunderbolt ports, you might be able to use two of these to connect multiple HDMI 2.1 displays.
Since the bandwidth requirements for the HDMI 2.1 features are so high, there aren’t many dongles available on the market.
Does An HDMI Splitter Reduce Quality?
No. An HDMI Splitter will not reduce the quality because HDMI uses digital signals which will either work or not. However, some HDMI splitters will set the lowest detected resolution as default on all connected displays.
For example, if you plug a 4K monitor and a 1080P monitor into an HDMI splitter, it might change the resolution on every monitor to 1080P. For more reliable quality, I recommend using a powered, high quality, HDMI splitter. Some models will set individual resolutions but most generic ones will only support one resolution at a time.
Does An HDMI Splitter Cause Input Lag?
A powered HDMI splitter will not create input lag because the signal is not being converted or processed. However, splitters that don’t have an external power source, or low-quality ones, can introduce input lag and other issues. Generally, most HDMI splitters do not add any noticeable input delay.
Conclusion
There are many different HDMI adapters that you can use to extend your displays. It might take a bit of fiddling around until you find a combination that works for you. Windows machines have the most options available, macOS is limited to expensive hubs.
image: “DN-HDMI423 HDMI selector/splitter” (CC BY 2.0) by cinz
