TechIntheBox 4K 1080P HDMI Splitter 1X2 Ports 50CM HDMI 1.4 HDCP 3D Video with DC5V/1A USB Power Adaptor HDMI Amplifier Splitter Cable

Quick summary:- No USB 5V 1A power supply included (title seems to indicate one is, but it just comes with a cable to connect to a USB power supply)- +5V output on HDMI is well below spec (I measured 4.45V on the output with a steady 5.05V going in on USB)- Couldn't muster 4K reliably (I could only get it to work at 1080p, and that was after I modded the hardware to use less power -- I could only reliably get 720p prior to that).- If you're desperate, you can take the box apart and stick in a longer HDMI cable on the input. It's got an HDMI receptacle inside the box.Here's my experience with this in more detail.I plugged it into my 4K HDMI test tool, and I couldn't get 4K to pass through. Then I tried 1080p -- no dice. Then 720p -- got a signal through, no pixel errors! Yikes... I'd really like to have at least 1080p. So I decided to crack it open and see what's going on with it.I open it up to find that it's a VERY shady little design. It's basically an HDMI receiver chip that strips off the HDCP content protection, and then goes into a chip that amplifies the HDMI signaling. I suppose if you have a use for something that strips HDCP, this could be a useful little box if you could get it to work reliably at the rate you need, but that wasn't my purpose (I need something to route clean HDMI from a camera to multiple receivers, so no HDCP concerns for my needs).Now that I think of it, it's possible that this box will only pass 4K if both outputs are connected... I might need to try that. I am still not very happy with this kind of design -- it's quite outdated, and chips from numerous vendors exist to do a proper HDMI splitting with redriving on each port, and this isn't what you're getting here. In summary, if you need top performance, you'll want to find a splitter that uses a proper HDMI splitter chip from the likes of Explore or Lontium, rather than this more hacky circuit they're using in this design.

This simple device performs exactly as it should. The only downside is that the input cable is hard wired in, meaning that if you want to change the input from one device to another, your only option will be to remove the cable from the output of one device to the output of another device (unless, of course, you use a switcher and plug this input cable to the output of the switcher). The box I'm using now does not support 4K, but it does have an HDMI input (female) so I can easily swap the output cable from one device to another.Bottom line - this thing works with 4K, sampled on Netflix from an Amazon Fire TV box. The device has the one input and two HDMI outputs. I've got two TVs in my home office and use this device to allow me to run the Tivo to either TV while the main tv has other options (FireTV, Roku, computer) and the secondary has basic cable running to it. This device also has a power input which is powered by a microUSB cable. My only complaints would be that (i) the cable is short (2 1/2 feet) and (ii) the connector is not standard, meaning it is difficult if not impossible to replace. Note, some TVs (one of my Sharp tvs) do not put out enough USB power to run this and you may need to use a 1 amp power plug to run this properly.The reason this only hits 4 stars is the short HDMI cable. It measures a bit shy of 18 inches. If the device had an input rather than a cable, the user would have a choice as to how long a cable to use. The hardwired cable leaves the user with no option here.The device outputs a proper signal so you can watch the same signal on both TVs at the same time.