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TV screen technology explained

What is 4K TV?

By Ben Stockton

Article 2 of 8

With four times the detail of high-definition telly, 4K Ultra HD is starting to become more widely available. But is it worth buying a 4K TV?

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Despite the fact that there's precious little content around to watch at the moment, if you're in the market for a new TV it should most definitely be a 4K set.

You'll also see names like Ultra HD, UHD and even 4K Ultra HD being bandied about - but they all refer to the same thing. This is a TV with a resolution of 3,840 x 2,160 pixels, more than 8m pixels in total, which is four times the number in Full HD (1,920 x 1,080).

What's so special about 4K TV?

Watching 4K TV at its best, you'll see everything on screen in crystal-clear clarity and sumptuous detail. There's a level of detail and depth that HD sets simply cannot achieve – at times, it almost feels 3D.

All the big brands, including Samsung, Panasonic, LG and Sony, now have large ranges of 4K TVs, from entry-level models to monster sets costing many thousands of pounds.

You'll generally find that 4K TVs are big-screen models of 40 inches or more. This is because to really appreciate the higher picture quality you need to watch it on a large TV, as it's rather lost on a small screen.

Best Buy 4K TVs

The best 4K TVs will put those extra pixels to good use, matching the pin-sharp detail with beautifully balanced colours and vivid contrast. But while a good TV will have great 4K picture quality, a Best Buy TV matches this with superb sound and easy-to-use smart TV features.

Below, we’ve included a selection of 4K sets at different prices to show you needn’t break the bank in the search for 4K quality.

Only logged-in Which? members can view our recommendations in the table below. If you’re not yet a member, you can get instant access by taking a £1 trial with Which?.

Best 4K TVs

Lowest price (in stock) £1,525.00
Which? score 80%
Reviewed Jun 2017
Best Buy
Picture quality:
4 out of 5
Sound quality:
5 out of 5
Ease of use:
5 out of 5
Screen size:
Member exclusive
Curved:
Member exclusive
HDR:
Member exclusive

One of the best performing TVs this year, it scores well across the board, plus it has dropped significantly in price since launch.

Lowest price (in stock) £2,150.00
Which? score 78%
Reviewed May 2017
Best Buy
Picture quality:
4 out of 5
Sound quality:
5 out of 5
Ease of use:
4 out of 5
Screen size:
Member exclusive
Curved:
Member exclusive
HDR:
Member exclusive

More than simply good looks, this vast 65-inch TV dazzles with both picture and sound quality. Match that with a slick smart-TV platform and this is one for the wish list.

Lowest price (in stock) £2,645.00
Which? score 75%
Reviewed Jun 2017
Best Buy
Picture quality:
4 out of 5
Sound quality:
5 out of 5
Ease of use:
3 out of 5
Screen size:
Member exclusive
Curved:
Member exclusive
HDR:
Member exclusive

This OLED is a real winner, with excellent sound and great picture quality to boot.

Lowest price (in stock) £699.00
Which? score 72%
Reviewed May 2017
Best Buy
Picture quality:
4 out of 5
Sound quality:
4 out of 5
Ease of use:
5 out of 5
Screen size:
Member exclusive
Curved:
Member exclusive
HDR:
Member exclusive

Matching a simple smart-TV platform with decent picture and sound quality is a winning formula. If you're looking for a new smart TV, this Best Buy must make the shortlist.

Lowest price (in stock) £497.00
Which? score 71%
Reviewed Sep 2017
Best Buy
Picture quality:
4 out of 5
Sound quality:
4 out of 5
Ease of use:
4 out of 5
Screen size:
Member exclusive
Curved:
Member exclusive
HDR:
Member exclusive

If you're looking for something a bit more affordable, this is one of the best value buys of the year. Sharp picture, pleasant sound, plus it's easy to use.

Lowest price (in stock) £397.90
Which? score 68%
Reviewed Sep 2017
Picture quality:
4 out of 5
Sound quality:
4 out of 5
Ease of use:
4 out of 5
Screen size:
Member exclusive
Curved:
Member exclusive
HDR:
Member exclusive

It misses the Best Buy mark by a few percent, but this TV is still one that we recommend taking a closer look at. It performed well across all our picture-quality tests, and comes equipped with an excellent smart TV system.

Not found the product for you? Browse all of our TV reviews

Where can I find 4K content?

Best Buy 4K TVs are outstanding, and you’ll be getting a great TV if you buy one. However, bear in mind that just as with HD in its early days, we’re still a way off settling down to our evening's viewing in 4K quality.

There are some big challenges ahead before 4K is a staple of most households’ TV watching. But content is becoming more widely available, be it through broadcast TV, ultra-HD Blu-rays and internet streaming:

  • 4K TV channels Some 4K TV channels are becoming available to watch on pay-TV services, such as BT and Sky, but there aren't many. Big technical challenges remain in introducing 4K channels on to subscription-free service Freeview, and we feel this will be a big factor in this technology going mainstream.
  • Blu-ray More and more 4K ultra-HD Blu-rays arrive on shelves every month, but you’ll pay a premium, not only for the discs but for the players as well. 4K Blu-ray players start at around £180 – check out our reviews to find the best one for you
  • 4K internet video streaming Content providers such as Netflix, Amazon Video and YouTube have already begun streaming content in 4K. But you'll need at least 15Mpbs broadband (ideally 20Mbps or higher) to get the best possible experience. Before more 4K channels become available, internet streaming will likely be your biggest source of 4K content.

Don’t Buy 4K TVs

4K is no assurance of quality – there are plenty of poor 4K TVs out there. Picture quality comes down to more than resolution alone, so simply looking for 4K certainly doesn’t guarantee you a great TV. 4K TVs can still fall foul when it comes to picture quality, including contrast and colour balance, as well as other factors including sound and ease of use.

We’ve seen a number of shoddy 4K sets in our lab, with some so bad we’ve made them Don’t Buys.

The table below rounds up some of the worst 4K TVs from our testing. Despite their 4K resolution, these TVs can have gaudy, unbalanced colours or poor contrast that looks washed out and drab.

4K TVs to avoid

Lowest price (in stock) £2,319.33
Which? score 49%
Reviewed Feb 2016
Picture quality:
3 out of 5
Sound quality:
3 out of 5
Ease of use:
3 out of 5
Screen size:
Member exclusive
Curved:
Member exclusive
HDR:
Member exclusive

This 65-inch set won't give you the stunning picture quality you'd expect from a 4K TV of this size. The lacklustre colour and contrast balance matched with the nasal sound leaves plenty to be desired.

Lowest price (in stock) £299.98
Which? score 45%
Reviewed Jun 2017
Picture quality:
3 out of 5
Sound quality:
2 out of 5
Ease of use:
4 out of 5
Screen size:
Member exclusive
Curved:
Member exclusive
HDR:
Member exclusive

This set definitely shouldn't be on your shortlist. Poor sound and a juddery picture, plus a lack of features make it one to avoid.

Lowest price (in stock) £269.00
Which? score 42%
Reviewed Aug 2017
Picture quality:
3 out of 5
Sound quality:
1 out of 5
Ease of use:
4 out of 5
Screen size:
Member exclusive
Curved:
Member exclusive
HDR:
Member exclusive

A popular name can't save this TV from being a Don't Buy, but it goes to show that no brand is too big to fail in our tests. The juddering picture and shoddy sound make this one to avoid.

Should I buy a 4K TV?

Many of today’s Best Buy TVs are 4K. This is because most new TVs from the big manufacturers are now 4K, with Full HD typically being available only on their cheaper sets. Plus, 4K TV prices continue to drop. So if you’re looking for a new TV, we’d recommend buying one with 4K.

But with HD still forming the bulk of content available to watch, if you’ve got an HD TV that you’re happy with, you shouldn’t feel the need to rush into replacing it with a 4K set.

New technology is emerging that can compress the huge amount of data involved in 4K into forms that are easier to distribute not just on television, but also on Blu-ray discs and over the internet.

Although it took HD TV more than a decade to become a mainstream after the first HD TVs launched in 1998, we don't think it will take so long for 4K ultra HD. You certainly won't be wasting your money by going for a Best Buy 4K TV, but just bear in mind the limitations in terms of 4K content to watch.

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