If you have one HDMI port on your game console, laptop, and cable box, you can still connect two or more monitors. You can use an HDMI splitter, HDMI adapter, or HDMI switch. An HDMI splitter will help you replicate the contents of your source devices on your two monitors.
Can you run two monitors off a HDMI Splitter?
An HDMI splitter takes an HDMI video output from a device, like a Roku, and splits it into two separate audio and video streams. Once split, you can then send video to two separate monitors from a single source.
How do I connect 3 monitors with HDMI Splitter?
Just plug the single USB end into your computer’s HDMI port, and plug each of your two monitors into each of the two HDMI ports at the other end of the adapter. There is one big limitation here. While it does let you extend your desktop to two other monitors, those monitors will both display the same thing.