4K refers to super-sharp display and video technology where the resolution is roughly 4,000 pixels wide. Detail is the whole point of 4K – most of the time, you won’t be able to see the pixels in a 4K display, so everything looks natural and sharp. It’s great for photos, videos and gaming for this reason, but actually it’s superior for just about everything – it’s nicer when text looks smoother on a computer, for example.
The vast majority of the time, 4K refers to a specific resolution of 3840 x 2160 (which is also known as ‘Ultra HD’) – this is the resolution of all 4K TVs and 4K video streams from the likes of Netflix or YouTube. Some cameras record in what’s often known as ‘Cinema 4K’, which is a resolution of 4096 x 2160. You may find that some computer monitors refer to themselves as 4K, and will have a horizontal resolution around 4,000 pixels, but have a different height to the resolutions mentioned above, such as ultra-wide monitors. The width is what makes something 4K or not.
You’ll mostly see 4K referred to in TVs of 40 inches and above, in computer and laptop monitors, on video streaming services, and in video recording on cameras or phones.
Latest about 4K
Star Trek fans shouldn't worry about Blu-ray, 4K and DVD releases being dropped for digital
With a Blu-ray, 4K and DVD release date for Starfleet Academy season 1 hanging in the balance, should Star Trek fans be worried about physical access? Not according to Jeri Ryan.
What's the future of 4K Blu-ray and physical movie media? I asked the people behind the tech
I dug into the future of physical movie collecting with the people behind the technology.
LG C6 vs Sony Bravia 7 II: I tested these TVs side by side, and OLED had better watch its back
As RGB LED takes the fight to OLED in 2026, I compared the LG C6 next to Sony's more affordable RGB TV, the Bravia 7 II.
I’m a trained TV calibrator, and here are the best TVs you can buy today
Top OLED and QLED sets to consider, from elite TVs to wallet-friendly options – all tested by us.
Who needs Dolby Atmos? These 6 4K Blu-rays support with DTS Master Audio surround sound (and 1 with stereo) are perfect for showing off what your your home theater can really do
While Dolby Atmos may have the name-power, its rival is no slouch either, so I picked my top 7 DTS-powered 4K Blu-rays.
Someone built a custom player for all 3D movie formats, forwards and back-compatible
An intrepid Redditor has built a 3D movie player that supports three different generations of 3D, with an eye to the future of TV and projector tech.
Here are 3 Batman 4K Blu-rays I'll be regularly watching until The Batman Part II's release
As Batman fans eagerly await The Batman Part II, now with a 2028 release, here are 3 of my favorite Batman 4K Blu-rays to watch at home
Someone polled 4K Blu-ray player owners about the reliability of different models over time
A reddit poll of Blu-ray owners shows a big difference in the reliability of different firms' devices over time
