If you're in the market for a new TV, you're probably thinking about getting a 4K or Ultra HD model. Is there a difference, and what exactly should you be looking for when you buy? Here's what you need to know before diving in.

What Do the "Ultra HD" and "4K" Labels Mean?

Let's start by defining "HD." High Definition Television (HDTV) is the standard that's been in use for over a decade, and you'll find it difficult to buy a TV that isn't at least "HD Ready," which means capable of displaying at a resolution of 1280x720 (720p).

Most modern TVs are at least "Full HD," which means capable of displaying at a resolution of 1920x1080 (1080p).

The "p" stands for "progressive," meaning that the entire image is drawn each frame. The alternative is "i" for "interlaced" (as in 1080i, another HDTV standard), meaning odd and even lines are displayed in alternate frames. This results in a lower quality picture.

Along those lines, the term 4K refers to any display format with a horizontal resolution of approximately 4,000 pixels. This is slightly confusing as TV resolutions, at least up until this point, have generally been referred to by the number of vertical pixels. TVs with this many pixels are "Ultra HD," or UHD for short.

Comparison of TV resolutions

This switch isn't entirely arbitrary. Unlike TVs, digital movie theater standards have traditionally emphasized horizontal resolution. The Digital Cinema Initiatives (DCI) standard is the most common for digital production and mandates a resolution of 4096x2160.

4K vs. UHD vs. 2160p

UHD-1 is the closest TV display standard to the DCI standard and refers to a resolution of 3840x2160. This resolution is four times the pixel count of Full HD. Most modern TV displays are UHD-1 as the wider aspect ratio of DCI 4K is not suitable for most TV content. However, they are both almost universally referred to as 4K.

UHD-1 is often referred to as 4K UHD or just 4K. Some people occasionally refer to UHD-1 as 2160p. When you see any of these terms, they typically mean the same thing. When it comes to TVs, there is no difference between 4K and UHD.

Note: There is also Full Ultra HD, sometimes called 8K, which refers to a resolution of 7620x4320. This is quadruple the pixels of 4K and sixteen times larger than Full HD. But 8K is still in a relatively infantile stage. For the most part, when you see the Ultra HD label on a Blu-Ray movie or elsewhere, you can take it to be referring to 4K.

Can You Notice the Difference Between HD and UHD?

Comparison btween HD and UHD

While the content situation has improved, most people probably won't notice the higher resolution even when watching native 4K content.

If you're sitting less than six feet away from a 55-inch TV and you have perfect vision, you might notice a difference. At greater distances, smaller screen sizes, or less clear eyesight, you probably won't. In most circumstances, the difference is marginal and may not be worth the cost of upgrading.

Yet there may be other valid reasons to make the upgrade. The higher resolution may not benefit you much, but there are other features of UHD TVs that may persuade you. Not all UHD TVs have them, however, so it's important to tread carefully.

Ultra HD Premium

The new Ultra HD Premium standard specifies increased color depth (over a billion colors) and a higher dynamic range so the quality of the picture should be noticeable compared to prior standards.

The Ultra HD Premium logo is a guarantee that the device meets the standards and is able to display UHD content as it's meant to be seen. Manufacturers like LG, Panasonic, and Samsung have embraced the Ultra HD Premium standard. So have content providers like Netflix, Warner Bros, and 20th Century Fox.

home-entertainment-2016-ultra-hd-premium

Sony doesn't use the logo even though it was part of the UHD Alliance that developed it, but many of its TVs meet or exceed the required specifications.

Do You Need a 4K or Ultra HD TV?

4K content can stream to a 1080p TV. Ultra HD Blu-Ray disks play on older televisions. The latest generation of video game consoles will work as well. If you already have a TV, you can continue to use that TV and still view whatever you want.

Ask yourself if 1080p looks insufficient. If you think HD content still looks beautiful, you may do well to save your money. Most content is still made with 1080p displays in mind. And you won't be doing yourself any favors buying a 4K TV if you primarily watch DVDs, which max out at 480p.

But there are reasons to want an UHD TV. If you have a home theater room where you're seated further back from the screen, or you're in the market for a new TV regardless, it makes sense to go for 4K. If you enjoy playing games at their maximum resolution, that will soon mean getting a 4K TV. You can even get a 4K TV for under $600.

A Few Other Points to Consider

If you do take the plunge and treat yourself to a new UHD TV, you may need to make some other upgrades to get the most out of it. Your existing devices, cables, and services will all still work but they may not allow you to view UHD-quality pictures.

While HD content that's been upscaled to UHD will look fine, the visual quality is not on part with content natively produced in UHD.

That means to experience 4K you will have to do more than get a new TV. Here are other changes you may need to make:

  • You will need fast reliable broadband. 4K content requires more bandwidth than HD.
  • You may need to change your cable or satellite subscription plan to get access to UHD content. It will probably cost more.
  • Your old Blu-Ray player will also need replacing. UHD Blu-Ray players will upscale existing 1080p Blu-Rays as well as play the higher resolution (and more expensive) UHD discs.
  • You may want a new HDMI cable. While HDMI 1.4 is capable of displaying UHD resolutions, HDMI 2.0 is needed to display them at 60 frames per second.

Streaming platforms like Netflix, Hulu, Amazon Prime, and Disney+ all have growing catalogs of UHD content. To take advantage of this, you'll need a streaming device that can handle UHD (unless your TV comes with these services built-in).

Here is our head-to-head comparison of four of the best 4K streaming devices on the market.