To connect anything to your TV, you're probably going to need HDMI cables. Gone are the days of multi-colored cables to deliver audio and video. HDMI covers both. Befitting its status of the cable of cables, it's everywhere. Even the checkout lines at grocery stores have HDMI cables. Looking closely at the details, there are a lot of numbers and abbreviations making for a confusing mess for anyone trying to figure out what cables to buy for their new TV.
Price has little to do with whether a cable will work with your new gear. Even the cheapest of cables should get you something, but to make sure you're getting 4K high dynamic range (HDR) video, you might need specific and better-made HDMI cables. These might not cost any more than the cheapest you can find, but are worth seeking out. Your old cables might work too, but again, not all will. So if you're considering getting a new TV, a 4K Blu-ray player, or a 4K HDR media streamer, you may also be in the market for new HDMI cables. Fortunately, you can get the maximum performance possible in an HDMI cable for less than $10.
I get into recommendations on new cables below, but first a bit of advice.
Just because you're getting a new TV doesn't necessarily mean you need new HDMI cables, even if you're upgrading to something with 4K and HDR. Over short distances, say under 6 feet (2m), just about any recent "High Speed" HDMI cable should work fine. "High Speed" is the rating used by HDMI companies to indicate cables that have the bandwidth to handle 1080p and greater resolutions.
You can think of bandwidth like a pipe. You need to be able to get a lot of "water" through the pipe with 4K and HDR content. A cable needs to be "big" enough to handle it all.
Unfortunately, there's no way to tell just by looking at a cable whether it can handle the deluge of data required for 4K and HDR content. Even if it says "High Speed" on the jacket, that's not 100 percent useful. A cable can be considered "high speed" if it passes 1080p, but not be well enough made to handle 4K. The only way to verify it works is to test it.
There are only two "fails" with an HDMI cable. The most likely is you won't get any signal at all: A blank or flashing screen. First, check that everything's connected correctly, and all your settings are correct.
Also remember, if one step in your chain isn't 4K HDR, nothing is. As in, if you connect a 4K Blu-ray player to an old sound bar and then to a 4K TV, you won't be able to get a 4K signal to the TV. Also, many TVs only have one HDMI input that's 4K. Check that, too. If all your hardware and settings are correct, it might be the cable, so you can skip to the next section.
The only other "fail" mode of HDMI cables is sparkles. This looks like snow on the screen. It can be heavy enough to look like static, like an old TV tuned to a dead channel, or it can be random-but-regular flashes of white pixels. This means you'll need new cables.
If the TV is receiving the same resolution you're sending it (e.g. the TV says it's 4K HDR when you're sending 4K HDR), you're all set. A different cable won't make that image sharper, brighter or anything else.
So lets say you don't want to worry about it, you don't want to risk a non-working new TV while you wait for ordered cables, or you're just pretty sure your current cables won't work. Here are some options.
There are cheaper options than what's listed below, but the ones here are from reputable companies that have great user reviews and have sold HDMI cables for years. They're also rated to have the bandwidth to handle 4K and HDR content. This is often listed as "18Gbps," referring to the amount of bandwidth possible.
Which is to say, if you just want the short answer and don't want to have to think about it, these are the best options, depending where you want to buy them. I used 6-foot/1.8m as the example for pricing, but each brand or outlet also offers longer and shorter options.
There are, of course, many other options.
If you want to keep hunting for the best deal, make sure the cable you're considering is either Premium Certified, says it can do 4K/60, or can handle 18Gbps bandwidth. And it's an added bonus if it has a warranty like the Amazon or Monoprice cables.
There's no such thing as HDMI cable "versions." As in, there's no such thing as an "HDMI 2.0" cable. The version numbers refer to the connections in your TV, receiver, sound bar, etc. So your TV and 4K Blu-ray player need to both have HDMI 2.0 to watch HDR content, but the cable connecting them couldn't care less. It's just a dumb pipe.
As long as that pipe is "big" enough, that is, has enough bandwidth, you should be good to go. The 18Gbps you've seen mentioned here came about with the HDMI 2.0 spec, so if a cable claims it, it's likely built to handle the additional data that HDMI 2.0 connections can provide.
If you need longer runs, consider active cables. These draw a bit of power from the HDMI connection to boost the signal. Monoprice, for example, has some that use Spectra7 tech, formerly RedMere. I recently bought one of these to connect my projector and so far it's working great. There's no specific distance over which you should get active cables. It's going to depend on your specific gear. A 25-foot/7.6m passive cable might work between one receiver and TV, but not a different receiver or different TV. Long active cables should work for everyone.
You might hear mention of HDMI 2.1, but for now don't worry about it. We're years away from products requiring the bandwidth available with an HDMI 2.1 connection. You're better off buying cheap cables now, and then in several years (or probably, many years), getting cheap HDMI 2.1 cables.
Lastly, if you want to run the cables through a wall, make sure you get HDMI cables specifically made for that. Check your local building codes for what you need.