Introduced back in 2002, the humble HDMI cable is widely seen as the default way of connecting various audio and video devices to your television.

They carry audio and video and are used to connect games consoles, steaming sticks, cable and satellite boxes and sound bars to your TV or projector. They can also be used to connect all of these devices to an AV amplifier, which then connects to your television and surround sound speakers.

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HDMI cables are available in various lengths and designs, with flat cables particularly useful for running under carpet, and their prices can vary significantly. There are also different standards of HDMI, with newer models capable of carrying more data to help feed 4K and even 8K televisions.

When creating your home entertainment system it is important to use the right types of HDMI cable and to understand the differences between each model. Otherwise, using the wrong type of cable may result in the picture shown on your television being of lower quality than what the TV is actually capable of.

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What does an HDMI cable do?

We thought we'd start with a simple question. HDMI is a digital standard for carrying video and sound from one device, like a game console or streaming box, to a television, projector, sound bar or amplifier.

Being digital, it is generally the case that the signal either gets from one device to another, or it doesn't. It isn't possible for video sent along an HDMI cable to become grainy or suffer from static, as used to be the case with older analogue connections. That said, content sent along a very long HDMI cable can suffer from issues, where tiny pieces of picture and audio data fail to arrive correctly. Thankfully, there are ways to get around this and we will explain more later.

If you don't want to use an HDMI cable to carry sound from one device to another, perhaps because you have a sound system that uses an optical cable, then it's possible to have a device like a game console send its picture over HDMI and its sound over an optical cable.

HDMI cables contain 19 connections to carry picture and soundiStock

What are the different types of HDMI cable?

As video resolution has increased over the years, and additions like HDR have been developed, HDMI cables have evolved to carry more data at a faster rate. Despite this, all HDMI cables use the same physical connections. There are currently three types of HDMI cable to understand. The most basic is called HDMI v1.4 and it arrived in 2009

HDMI v1.4

This was the first type of HDMI cable capable of carrying a 4K (Ultra HD) image, but at just 30 frames per second (also known as 30Hz). Since most 4K content is best enjoyed at 60 or 120 frames per second (or even 240 with a high-end gaming computer), a v1.4 cable is not recommended for today's 4K content.

As such, if you have a 4K television you should avoid v1.4 HDMI cables entirely. Even when looking at HD content, v1.4 cables can't handle 10 or 12 bit color, so you'll be missing out on most HDR standards too, although Dolby Vision does work with v1.4.

If you need to plug a DVD player, an HD media streamer or an older game console like an Xbox One or PS4 into an HD television, then a v1.4 cable will do the job just fine, but for anything of higher quality you will need a different cable.

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HDMI v2.0

Next comes what is probably today's most commonly used version of HDMI, called v2.0. Released in 2013, these cables can handle 4K video at up to 60 frames per second, making them much more appropriate for today's media streamers and game consoles. They also support 10 and 12 bit color, making them compatible with HDR10+.

Things can get confusing with HDMI 2.0, as some manufacturers have pushed the technology further than others. For example, Sony devices support eARC lossless sound over HDMI 2.0, whereas other manufacturers rely on the newer and faster HDMI 2.1 standard to achieve this.

At this point it is also worth explaining that the HDMI socket of a device like a television or game console is also limited in what it can process, not just the cable itself.

For example, if you want to run your PlayStation 5 or Xbox Series X at 4K resolution and 120 frames per second, you need to have an HDMI 2.1 cable, but also a TV that meets the same standards and has an HDMI 2.1 socket. If you run the console through a sound bar or amplifier, that connection will also need to be HDMI 2.1. Some televisions have multiple HDMI ports, but not all of them will be HDMI 2.1 compatible, so you'll need to make sure you connect to the right socket.

HDMI v2.1

The new Xbox Series X and PS5 can benefit from HDMI 2.1 cables Microsoft / Sony

Speaking of 2.1, the latest and greatest HDMI standard arrived in 2018 and is what you'll need if you want to get the very best out of your home entertainment system. These cables can carry data at a massive 48Gbps, up from 18Gbps for HDMI 2.0.

They are capable of transmitting 4K video at 120 frames per second, making them perfect for the latest generation of video game consoles or for high-end PC gaming. Speaking of gaming, cables meeting the v2.1 standard can also handle variable refresh rate and will tell your TV to switch to their gaming mode when a console is detected.

They can also manage 8K at 60fps and even support 10K video too, although there are no such televisions available today.

HDR quality is improved with HDMI 2.1 cables, with support for Dynamic HDR if your TV and output device (like a console or streaming box) also supports it.

HDMI 2.1 is currently the gold standard, but you only really need these cables if you own a next-generation game console like the PS5 or Xbox Series X, and you want to play games on a TV that supports 4K at 120fps (120Hz), which few do at the time of writing in early 2021. However, many televisions newly announced for 2021 and due out later in the year will support HDMI 2.1.

If you want to futureproof your system then you could invest in HDMI 2.1 cables now – especially if these cables need running under floors or through walls, where upgrading at a later date might be tricky. Remember, a 2.1 cable will work just fine with inferior hardware, like an older game console and TV, you'll just be limited to whatever those devices are capable of outputting, instead of what the cable can transmit.

Are expensive HDMI cables worth it?

The short answer here is no. A decade ago, electronics retailers were guilty of trying to sell cables costing $50 or even $100 to connect a DVD player to an HD television. They would claim the cable's gold coating would help produce a better picture, but this is widely regarded as untrue.

At their simplest, HDMI cables contain 19 pieces of wire. Each wire has a role to play in carrying a movie, game or TV show from one device to another, but they are all built to carry an electrical signal. The cable itself does no processing of this signal at all; it is just carrying it from one place to another.

It is important to remember that a poor quality or damaged HDMI cable might fail to transmit the occasional bit of data, but we're talking a single faulty pixel of one frame of video, so hardly something you are going to notice.

Expensive cables don't improve image or audio quality, but very cheap ones might produce a worse experience. That said, I live in the UK and for many years used HDMI cables bought for £1 ($1.40) each and never had any issues with game consoles and an HD TV.

That said, there are some occasions when spending a little bit more money makes sense. You might want an HDMI cable with a connection fitted to a hinge, thus helping fit the cable to a TV mounted closely to a wall. Similarly, you might want to buy flat HDMI cables to run under a carpet.

Long, Active HDMI cables can be useful for ceiling-mounted projectors Optoma

Do you need an active or passive HDMI cable?

If you plan to build a home entertainment system with a projector located a long way from your input devices (like a cable box and game console), or an amplifier across the room from the TV, you will need long HDMI cables.

Being a digital signal, picture and sound sent along a regular, passive HDMI cable can fade over long distances, such as 20 feet or more. To solve this, active HDMI cables transmit power to boost the signal; this power is often only sent in one direction, so the cable needs to be attached the right way, with power and data flowing from your output device, like a game console, to the TV or projector.

Buying the right HDMI cable for your setup

Although not all do, the packaging of many HDMI cables include identifiers created by the HDMI Licensing group. These include High Speed and Ultra High Speed, with each of these labels helping to identify what the cable is capable of.

High Speed cables are HDMI 2.0, which means they can carry data at up to 18Gbps and handle 4K images with HDR. For most home entertainment systems, this is exactly what you need.

These can be bought for around $10, with this 6ft AmazonBasics cable currently priced at $7.99. Alternatively, this 6.6ft braided High Speed HDMI cable is $11.99, and this two-pack of 6ft High Speed cables is reduced to $10.99.

If you own a new game console and a television that supports HDMI 2.1, you will want to buy Ultra High Speed cables, as they can handle 4K at up to 120fps.

Ultra High Speed cables with HDMI 2.1 capabilities cost more, but are still significantly less than the overpriced cables offered a decade ago. This 6ft HDMI 2.1 cable from Belkin is $40, while this 10ft option from Zeskit is $26.

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