HDMI Splitters do not automatically reduce quality because they are copying a digital signal. But using lower quality hardware or a non-powered HDMI Splitter is less of a guarantee. Splitters used with very long HDMI cables may have signal quality issues due to the cable length.

Do HDMI adapters degrade quality?

An HDMI coupler will degrade your signal. And through use, the HDMI connector will loosen and may break when cables are tugged. The best solution is an HDMI Balun kit, which uses Ethernet to transmit the signal between your devices instead of an HDMI cable.

Do HDMI splitters actually work?

A splitter will duplicate a signal and send it out through multiple HDMI cables. ... The splitter won't convert the signal to 1080p just for that TV. In theory you shouldn't have copy protection issues… in theory. You should be able to send any content you want through a splitter to multiple TVs.