If you’re buying a television for the first time in a few years, get ready for the brave new world of even higher-tech TVs.

Almost all TVs—especially the bigger ones that you might want for a living room or home theater—now come with a collection of advanced features.

For one, most are now “smart,” meaning they let you stream shows from services such as Netflix without plugging in extra equipment.

Second, they’re also 4K—aka ultra-high definition, or UHD—with four times as many pixels as regular HDTVs. The extra pixels, or tiny dots that make up the picture, allow the sets to display sharper, more detailed images, especially on TVs with bigger screens.

Best of all, say our TV testers, many of today’s newest TVs can show images with high dynamic range, or HDR. When done right, HDR boosts a TV’s brightness, contrast, and color, making the pictures on the screen look more like real life.

But all those features and acronyms can also make buying a TV more daunting than it deserves to be. And not all of the new TVs perform equally well.

Here’s what you need to know to make a good choice.

What Makes HDR So Special?

When HDR is at work, you’ll see details that might not otherwise be obvious, from the texture of the brick on a shady walkway to nuances in the white clouds in a daytime sky.

You’ll also see brighter, more realistic “specular highlights,” which are glints of light, such as the sun’s reflection off a car’s chrome bumper or an airplane wing. With HDR, those highlights pop; without it, they wouldn’t stand out against other bright objects.

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HDR does all that by increasing the contrast between the brightest whites and the darkest blacks a TV can produce. That’s where the “dynamic range” in the name comes from.

“When done well, HDR presents more natural illumination of image content,” says Claudio Ciacci, who heads the Consumer Reports TV testing program. “HDR can flex its dynamic-range muscles in strong sunlit scenes that push the TV’s contrast to the limits,” he adds, “but you’ll also see HDR’s subtler benefits on more simply lit scenes.”

Typically, HDR TVs also produce more vibrant, varied colors than other sets. That’s because HDR is often paired with “wide color gamut,” or WCG, capability.

Standard HDTVs can display about 17 million colors, but those with WCG can display up to a billion. That’s like giving your TV a larger box of crayons to play with.

But you won’t see all that fantastic contrast and color every time you turn on the TV. You have to be playing a movie or TV show that has been mastered to take advantage of HDR and WCG. Those offerings are a bit thin right now, but a lot of new content is expected later this year and in 2018. (Find out where you can watch 4K content with HDR.)

A TV tester wheeling a 4K HDR TV into a CR TV lab.
Photo: Brian Finke

Types of HDR

So far we’ve been talking about HDR as if it was just one technology, but there are a few types of HDR, each following a different set of technical specs.

One type, called HDR10, has been adopted as an open standard. It’s free to use, and all 4K TVs with HDR support it. That’s also true of all 4K Ultra-HD Blu-ray players and HDR programming, so you won’t be stuck with a set that can’t play HDR.

But some TVs also offer another type of HDR, called Dolby Vision, which is being promoted as an enhanced version of HDR10. Companies pay a licensing fee to use it. On paper, it has some advantages. In particular, it supports “dynamic” metadata, where the brightness levels for a movie or show can be tweaked scene by scene. In contrast, HDR10 uses “static” metadata, where brightness levels are set for the entire movie or show.

Dolby Vision won’t be alone in using dynamic metadata, though. There’s a newer version of HDR10, called HDR10+, waiting in the wings that to do the same thing, making HDR10 more like Dolby Vision. We’ll have to see whether any companies in addition to Samsung, which developed HDR10+, adopt it.

Finally, you may hear something in the coming months about one more HDR format, called, called HLG (hybrid log gamma). It could be important if it’s adopted for the next generation of free over-the-air TV signals, which will follow a standard called ATSC 3.0. Some TVs already support HLG, but it looks like others will be able to get firmware updates if necessary. This only matters for people who get TV through antennas, which are making a comeback. 

Yes, that all sounds complicated.

But there’s some good news. First, your TV will automatically detect the type of HDR being used in the content and choose the right way to play it. No fiddling required. 

Second, the type of HDR doesn’t seem to be too important right now. What we’ve seen in our labs is that top-performing TVs can do a great job with either HDR10 or Dolby Vision. The quality of the TV is more important than the type of HDR it’s playing.

Our advice: Buy the best TV you can regardless of the type of HDR it supports.

Are All HDR TVs Created Equal?

No. Our tests show that not every TV with HDR written on the box produces equally rich, lifelike images. 

First of all, TVs are all over the map when it comes to picture quality, HDR or no HDR. But there are also challenges specific to this technology.

Most notably, a TV might not be bright enough to really deliver on HDR. To understand why, you need to know your “nits,” the unit used to measure brightness.

Better-performing HDR TVs typically generate at least 600 nits of peak brightness, with top performers hitting 1,000 nits or more. But many HDR TVs produce only 100 to 300 nits.

With an underpowered TV, the fire of a rocket launch becomes a single massive white flare. With a brighter television, you’d see tongues of fire and smoke, as if you were really there.

“The benefits of HDR are often lost with mediocre displays,” Ciacci says.

How Can I Tell a Great HDR TV From a Bad One?

Unfortunately, you can’t just read the packaging—or even rely on how the picture looks in the store.

Though some TVs carry an “Ultra HD Premium” logo, indicating that they’ve been certified as high-performance sets by an industry group called the UHD Alliance, not all companies are going along. For example, LG and Samsung participate in the program; Sony and Vizio don’t.

What to do instead? Check our TV ratings and buying guide.

As you’ll see, the TVs with the best HDR tend to be the priciest. But there are also some good choices for people who want to spend less. And if you’re buying a smaller set, or just want to wait on 4K and HDR, you can find several good—and inexpensive—options.

Editor’s Note: This article also appeared in the November 2017 issue of Consumer Reports magazine.