Updated

If you’re considering a 4K TV, which has four times as many pixels as a conventional 1080p HD set, you may be expecting to instantly see extra detail and sharpness on every show. Not so fast.

No major broadcast network is presenting content with 4K, or ultra-high-def (UHD), resolution. Elsewhere, though, the number of 4K videos you can watch is increasing rapidly. You can now buy UHD Blu-ray players and 4K titles, and some TV service providers—mainly DirecTV—are offering 4K channels.

But you'll find much more of this material on streaming video services. Companies such as Amazon and Netflix have been moving quickly to add to their rosters of 4K movies and TV shows. Many of these programs also support high dynamic range, or HDR, a technology that allows for more contrast between bright and dark areas of the picture. That brings greater realism, detail, and vibrancy to many scenes.

Here's a rundown of 4K videos that streaming services are rolling out.

Amazon
The online retailer says it will have hundreds of 4K series and movies available by September, and up to 150 hours of HDR content to feed the two competing HDR standards, HDR10 and Dolby Vision. TV series in 4K include "Mozart in the Jungle" and "Transparent." The good news for Amazon Prime subscribers is there’s no extra charge for 4K.

FandangoNow
FandangoNow, formerly M-Go, says it already has hundreds of 4K videos, including some that support the HDR10 format. Titles, not exclusive to this service, include "The Martian," "The Revenant," and "Life of Pi." The company charges $1 or $2 extra to rent 4K titles, and $5 or so more for purchases. Right now it’s the only service that supports Vidity, a new 4K and HDR download service.

Netflix
The streaming leader says it will have more than 600 hours of 4K content by the end of the year, double what it had in 2015. And you can already get 4K streams of original series such as "House of Cards," "Grace and Frankie," and "Jessica Jones," plus movies including "Crouching Tiger, Hidden Dragon: The Green Legend." To get 4K TV shows and movies, though, you need to subscribe to Netflix’s $12-per-month premium plan. Netflix supports both HDR10 and Dolby Vision—two competing standards for HDR —and says it’ll have 150 hours of HDR content by year’s end.

Sony Ultra
Sony’s 4K streaming service, which supports HDR10, has about 100 films and TV shows in 4K. There are no rentals, only purchases, and movies cost about $30 each. Sony says about half of its titles have HDR, and that all Sony Pictures 4K and 4K HDR titles will be available through Ultra.

UltraFlix
Parent company Nanotech brags that its UltraFlix service has the largest 4K Ultra HD library of streaming content available. Titles include 4K nature documentaries, including dozens of titles originally created for IMAX, plus concerts, music videos, Hollywood movies and TV shows. Rentals cost anywhere from $1 to $10, with a 48-hour viewing window.

Vudu
Vudu was the first service we saw support Dolby Vision HDR. It has a number of major movies and TV shows available to own and rent in “Vudu UHD,” its moniker for 4K titles with Dolby Vision. Titles in the library include "Mad Max: Fury Road" and "The Lego Movie," Vudu UHD titles cost a bit more, typically about $10 to rent and $30 to own a movie. Vudu says it has deal with Warner Brothers to provide titles in the Vudu UHD format.

YouTube
YouTube was offering 4K videos as far back as 2010, when there weren’t really many TVs to play them on. Now it’s got hundreds of thousands of 4K videos, and even a smattering of 8K content (don’t ask). Not surprisingly, YouTube is heavier on user-generated content than blockbuster movies and TV shows, but then again, it’s free. It says HDR is on its way, though there's no timetable for its arrival.

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