4K vs Full HD vs HDR: Do You Really Need 4K?

It's the number of pixels in the picture: HD is 1280×720, Full HD is 1920×1080 and 4K is 3840×2160, four times Full HD. More pixels means sharper fine detail, especially on large screens.

HDR (high dynamic range) doesn't add pixels; it improves light and colour: brighter highlights, clearer detail in dark scenes and richer colours. Many viewers notice HDR more than the resolution jump. The main HDR formats:

• HDR10: the baseline format, supported by almost every HDR device.
• HDR10+ and Dolby Vision: advanced formats that adjust the picture scene by scene, supported by many TVs and devices such as the 3rd-gen Xiaomi TV Box S.
• HLG: a format designed for live TV broadcasts.

A 4K TV isn't enough; you need all of these together:

1. A 4K TV, ideally with HDR.
2. A 4K streaming device such as a Fire TV Stick 4K or Google TV Streamer, plugged into a 4K-capable HDMI port.
3. A stable connection of at least 15 Mbps, ideally 25 Mbps for live streams.
4. Content actually filmed and streamed in 4K.
5. A subscription tier that includes 4K, such as Netflix Premium.

If one is missing you'll watch in lower quality even if everything else is 4K. Speed details in our internet speed guide.

No. Most live TV channels broadcast in HD or Full HD, and 4K is usually limited to selected major matches and events and part of movie and series libraries. So when any service advertises "4K channels", it usually means a set of channels, not all of them. That's normal across services and doesn't mean poor quality; Full HD on a good screen looks excellent.

• Worth it: on a 55-inch or larger screen with fast, unlimited internet, for movies and big matches.
• Usually not: on a 43-inch or smaller screen, if you sit far away, or on a capped plan; an hour of 4K uses up to 7 GB versus 3 GB for HD.

Usage details in our streaming data usage guide.