From the streaming box to the projector: HDMI 2.0 cables for 4K 60 Hz HDR, Ultra High Speed HDMI 2.1 for 8K, 4K 120 Hz and eARC, CL3 in-wall rated cables that meet code behind drywall, active and hybrid optical cables that hold full bandwidth over 50 to 150 ft, plus splitters, extenders and DisplayPort to HDMI adapters.
Length is the decision
Under 25 ft, a certified passive cable in the right tier is all you need. Beyond that, conductor gauge and then active or optical construction decide whether 4K arrives intact; optical cables are directional, so install them source-to-display. Our guides: HDMI for long runs, ARC vs eARC for soundbars and what each HDMI version changed.
Start here: our guide to best HDMI cable for a 4K TV.
Common questions
Do I need a CL3 cable behind the wall? Yes. CL2 or CL3 is the fire-safety rating building codes require for in-wall installation. It says nothing about picture quality, only where the cable may legally go.
Will an HDMI 2.1 cable make my 4K 60 Hz TV look better? No. It carries more bandwidth than the TV can use. Buy 2.1 for 4K 120 Hz, 8K or eARC; buy a Premium High Speed 2.0 cable for a 4K 60 Hz set.
Length decides the cable
| Run |
4K 60 Hz HDR |
4K 120 Hz, 8K or eARC |
| Up to about 15 ft |
Premium High Speed, 18 Gbps |
Ultra High Speed certified, 48 Gbps |
| 15 to 25 ft |
Premium High Speed in a heavier gauge |
Ultra High Speed, shortest length that reaches |
| 25 to 50 ft |
24 AWG passive, or an active cable |
Active or hybrid optical |
| 50 to 150 ft |
Active optical |
Active optical, and mind the direction |
| Inside a wall, any length |
CL2 or CL3 rated |
CL3 rated; optical cables are usually not in-wall rated |
More common questions
Does an optical HDMI cable need power? Most draw the small amount they need from the HDMI port itself, so no separate supply is required. What they do need is to be installed the right way round: the source end and display end are not interchangeable.
Which end goes to the TV? On a directional active or optical cable, the ends are marked, usually "source" and "display". Getting it backwards produces no picture at all, which is the most common support call on these cables and the easiest to fix.
Do I need eARC for Dolby Atmos? For the full-bandwidth, uncompressed formats, yes. Ordinary ARC does not have the bandwidth. Both the TV and the soundbar or receiver must support eARC, and the cable between them should be Ultra High Speed.
