What is HD TV?
By Andrew Laughlin
"If you're upgrading from standard-definition, you'll be amazed by the increase in sharpness and detail on screen in HD TV."
Ready to buy? We've got hundreds of expertly-tested HD TVs to browse across all types, brands and price ranges in our TV reviews
Clearer, sharper pictures
High definition television is clearer, sharper and more lifelike than standard definition TV. This is because it is higher resolution, which means there's more information available to form the picture.
The two most common types of HD are 720p (also known as HD-ready), which is slightly more than twice the resolution of standard definition, and 1080p (or Full HD), which has over five times as much picture information. If you want the very best experience, buy a 1080p TV.
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How do I get HD TV?
To watch HD TV you'll need an HD television and something to watch in HD format, either an HD TV programme on an HD TV channel (such as BBC One HD), a film on Blu-ray disc, or an alternative HD source, such as HD video streamed over the internet to your TV.
All new flatscreen TVs sold these days are HD compatible, but they come in two different types – HD-ready and HD-ready 1080p. The difference is to do with the screen’s resolution.
Screen resolution is the number of pixels, or lines displayed on the TV, and is expressed as ‘width x height’. Full HD screen resolution, sometimes referred to as HD-ready 1080p, is 1,920 x 1,080 pixels, while HD-ready is 1,024 x 768.
Full HD TVs have superior picture quality when watching HD TV broadcasts on Sky HD and Freeview HD, for example, or movies on Blu-ray disc.
Cheaper, 'HD-ready' TVs have a minimum screen resolution of 1,024 x 768 required to display HD TV, but cannot show Blu-ray movies in their full picture quality. These TVs tend to be smaller screen models as it’s harder to physically see the screen resolution difference at that size.
The best HD TVs are exceptionally crisp with outstanding colours, but buying an HD TV alone is not a guarantee of quality. Be sure to check our LED, LCD and plasma TV Best Buys to see which offer the best picture quality.
What HD TV channels can I get?
HD TV is available via Sky or Virgin Media pay-TV subscription services, or without monthly subscription from Freeview HD or Freesat HD. It is worth noting that most HD TV is not actually broadcast in Full HD (1080p) due to the large amount of data that would involve. Instead, it is aired at a slightly reduced quality, known as 1080i.
Freeview HD, Freesat HD and Freesat from Sky offer a small number of HD channels, including BBC One HD, ITV HD and Channel 4 HD. You don't pay a monthly fee for these, but you may need to pay for set-up equipment such as a Freeview HD set-top box or a satellite dish.
If you sign up for a Sky or Virgin Media TV package, you get a much larger number of HD channels - over 65 with Sky's most expensive package.
The crucial thing to remember is that standard-definition channels are still being broadcast and won’t become HD simply because you’re watching them on an HD TV. A good indicator is usually the name of the channel, as high definition channels will almost always have ‘HD’ after their name.
What are Blu-ray discs?
Blu-ray discs are essentially high-definition DVDs that almost always display at 1080p resolution. This means that films on Blu-ray are sharper and more detailed than standard-definition DVDs, and even HD TV; especially if you use a Which? Best Buy player.
A large number of Blu-ray films are now available, from the latest Hollywood blockbusters to old classics, and nearly all new film releases are made available on Blu-ray, as well as DVD.
An increasing number of 3D Blu-rays are also available, though you'll need a 3D TV and a Blu-ray player that supports 3D to be able to watch them.
LED vs LCD vs plasma TV - which should you choose?
LED, LCD and plasma at the three main types of TV, and each type has its own unique strengths and weaknesses.
LCD TVs use a large light source to help make up the picture you'll see on screen. Most manufacturers no longer make the rather bulky LCD TVs, instead favouring newer technologies.
LED TVs are essentially the next evolution of LCD TVs. They use different backlight technology - tiny LEDs instead of traditional bulbs - enabling them to be slimmer, have brighter pictures and use less power.
Plasma TVs use different technology to LCD and LED. They're beloved by TV buffs for their cinematic picture quality, with deeper black areas on screen and smoother motion. Just like LCD, plasmas TVs are on the way out.
See our in-depth comparison of all TV types in our LED vs LCD vs plasma TV guide.
What size TV is best for HD?
For the best HD experience, go for as big a screen as possible because more screen space brings out the extra detail of HD that can sometimes feel subdued on a smaller model. Make sure, though, that you have enough room to accommodate a large TV.
If in doubt, a good rule of thumb is to measure the distance between your sofa and where you TV will stand. Ideally you should then buy a TV with a screen that’s around a third of the length measured.
If you sit around 10ft from your TV, for example, then a 46-inch TV should suit your room perfectly. Use our What size TV should I buy? interactive tool to help you choose.