Differences between SD, HD, 4K and 8K

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1200p, Ultra HD, 4K…? Image quality, video resolution, pixels…? Is the difference between 4K and 8K really palpable? Do I need my videos to have a certain quality to be better positioned?

There are many questions related to video resolutions, because, in the same way, there is a great diversity of them, with differences that are not entirely clear.

Just walk into an electronics shop, go to the TV area and be delighted by the range of possibilities, both in terms of price, size and resolution.

If you’re a computer expert, you will probably not have so much difficulty in choosing the best one that suits your needs; however, if this is not the case, you will need to go to the shop assistant to clarify many concepts and guide you in your decision.

Also, although everyone is able to realize whether the video they are watching has a good image quality or not (by clear visual criteria), there are many cases of people in charge of a business who are not really aware of the impact and influence that the finished product aspect of their videos can have as a marketing strategy to attract potential customers.

We will provide below answers to all the questions mentioned above so that, when it comes to publishing a video, you have all the necessary information about how image resolutions work, the differences between them and which is the best option according to your needs.

Basic concepts.

In this article we explain the differences between different video resolutions, so this is the key concept. However, to understand what it is all about, you first need to understand other aspects, such as screen proportions and pixels:

Screen proportions

Screen ratio refers to the size of the television, the relation between width and high. It is closely related to picture resolution because certain ratios are made to reproduce certain resolutions, so that the picture is seen without distortion.

The oldest format is 4:3 (measuring 25% more in width than in height), used in old televisions, with a quadrangular aspect ratio.
Later, the best known and currently used format appeared, the 16:9 format (they are almost twice as wide as they are tall), with a more panoramic screen.

You may ask yourself,

Why am I interested in knowing the screen proportions, if what I really want to know is the differences between resolutions?

Well, you need to take this into account, because depending on the image resolution you choose, you will have to have a device with a suitable proportion to enjoy the content at 100%.

Later on we’ll go into discovering each of the image resolutions, but, for the moment, we can say that all resolutions use a 16:9 aspect ratio, except for the SD format (it uses 4:3).


A pixel, technically described, is the smallest uniform unit of color that makes up a digital image. In layman’s terms, a pixel is a square of the same color, so a screen image is made up of several pixels of different colors.

However, we are not able to see these pixels with the naked eye, because they are unified in such a way that a clear and homogeneous image is displayed.

Here is a clear example:


Thus, when we talk about resolution -also called clarity or definition- of the image, we refer to the total number of pixels shown on a screen of any electronic device: mobiles, tablets, televisions… and, depending on the degree of resolution of this, it will be possible to achieve one video resolution or another; since the number of pixels of a screen is almost always the same as that of videos (this means that a screen with less image resolution than that of a video will not be able to make the most of its quality).

The difference between the level of detail or image quality lies in the number of pixels you have, because the more pixels (or “squares”) you have, the sharper and clearer the image.

This explains why older videos show more blurred images than can be seen today (the number of pixels was much smaller).

To express the type of resolution, two specific numbers are used: the first refers to the number of pixels in each line, and the second refers to the number of pixels in each column. These two are multiplied together, resulting in the following expression: 1920 x 1080 pixels.

Sometimes, it is shortened, showing only the vertical pixels. Taking the previous example, its image resolution would be: 1080p.

The last thing to take into account is that the higher the resolution of a device’s screen, the more power its hardware will need to play the video correctly and, therefore, the more battery it will use. Therefore, a mobile phone can display very good quality videos, with the cost of faster battery consumption.

Importance of picture quality.

As we said, many years ago there was no great concern for image quality, as televisions, for example, were distinguished from each other only because their image was in black and white or in color (a whim that only a few could afford).

However, with advances in technology, the quality of videos and images has been increasingly improved with the idea of providing a much better image for the viewer.

As a result, it is now easy to see the difference between a multimedia resource with the lowest possible resolution (SD) and one with 8K sharpness. See for yourself with the comparison below:

When you have a business you want to give the best possible image of your brand, capture the attention of potential customers, convince them that you can offer them just what they are looking for. Thus, it is not only necessary to have a good slogan, quality products and “people skills”, but also a letter of introduction in the form of a visual resource that shows professionalism.

A corporate video with poor image definition (despite meeting all the characteristics of good marketing) will not have the same acceptance as a video with clear colors, little blurring and in which the objects that appear are well defined.

Image resolution formats.

Although in this article we will focus on explaining in detail the characteristics of the most common formats (SD, HD, 4K and 8K), it is necessary to know that there are many other formats, such as those based on VGA -Video Graphics Array-, which are currently of little use given the great popularity of the previous ones.

Thus, we will go through each of the different resolutions, from the one with the lowest number of pixels up to 8K.

SD or "Standard Definition"

This standard definition was one of the first low-resolution formats and consists of 640 x 480 pixels. It is the one offered by the old DVDs.

HD or “High Definition”.

This format marks a new stage in the evolution of video and screen definitions

It is the first high-resolution standard, going from the 640 x 480 pixels of the SD format to 1280 x 720 pixels (better known as 720p). It is one of the formats most commonly used in televisions and computers until the 4K format appeared.

4K or “Ultra High Definition"

The Ultra HD format is more commonly known as 4K.

It is the format most commonly used in modern televisions. Its picture definition is 3840 x 2160 pixels.

Its nickname “4K” is due to the fact that this format originates from the film industry, whose screens offer images of 4096 x 2160 pixels. Therefore, a 4K resolution refers to pixels that, horizontally, almost constitute 4000.


This image resolution is the newest of all, the newest, the most surprising.

It is the format that is appearing in new, very high-end, large-screen televisions. It consists of 7,680 × 4,320 pixels, four times more than its predecessor.

Which is the best screen format? .Advantages and disadvantages of each one.

The easiest thing to say after the brief description of each of them would be that the best format of all is 8K, because, as you know, the more pixels, the better the video quality. However, you should be aware that each of the formats also has certain disadvantages, which might make you choose one over the other.

In order to make it more visible, we have compiled all the advantages and disadvantages of each of them in a table. In addition, later on, we will dedicate an exclusive section to identify the differences between the different formats, so that you will be able to choose the one that best suits your interests.

SDThe files used are smaller and lighter, so they can be transmitted more smoothly.

Totally disused.

Very poor picture quality.

Unclear colors


Good picture quality on small screens.

Affordable TV prices

Pixels can be seen if the image is viewed from a short distance.

Affordable prices for devices in this format.


Great depth of color.

Numerous multimedia resources available in this format.

With the emergence of 8K it will be used less and less.

Somewhat high prices.

Files in this format are quite heavy and take up a large amount of space.


You can take advantage of audiovisual resources in 4K format.

It offers the best image quality.

Very realistic and bright colors.

There is still not much 8K content in Spain.

Price is quite high.

Key differences.

Starting with the two older resolutions (SD and HD), we can see that the clearest difference between them is in the sharpness of the images, with HD predominating over SD, and this is particularly noticeable when viewing films which, visually, have very good characteristics.
Thus, High Definition files have a higher bandwidth, so they cannot be transmitted as quickly as Standard Definition files (an HD movie can weigh more than 1Gb, while another SD movie will not reach much more than 200MB).

If we take a leap from HD to 4K, we see that the difference is due to the increase in the number of pixels and the increase in the size of the screens: an HD screen continues with the 16:9 TV format, however, with the advent of 4K the screens are clearly larger, otherwise, two black stripes will appear (top and bottom of the screen).

Finally, the question on everyone’s mind when it comes to resolutions, which is probably why you are reading this article, is:

Is there really a difference between 4K and 8K resolutions?

Theoretically, there is a difference, as 8K has four times as many pixels as 4K, which gives a much sharper and more detailed image.

However, this difference is only noticeable if you get very close to the screen, at a distance of about half a meter.

Furthermore, 8K is found in very few places, two to be precise: YouTube and certain computer games; while many platforms such as Netflix, Amazon Prime Video and consoles offer the 4K format.

All this, plus the large price difference between them, leads us to think that it is not really worth spending a few euros more on an 8K resolution device until a few years have passed and it continues to evolve.

So what resolution should I choose to produce my videos?

As a good video producer, you will know that there are several platforms on which you can advertise your work, the best known and most used being YouTube. So, no matter what your needs and objectives are, it is essential that your audiovisual resources meet certain characteristics to reach the maximum audience and get good feedback.

First of all, it should be clarified that YouTube does not require a minimum resolution for its content, so the decision you make when choosing the appropriate resolution will be marked by clear guidelines.

On the one hand, ideally, people should be able to view the content in good definition, in 4K – for which you should record your video in a resolution of 2160p. However, this has some consequences: it takes up a large amount of storage, high data consumption when uploading the video and the need for a good internet connection when posting it. In addition, not everyone will be able to play the video at this resolution due to the type of device from which they view it.

On the other hand, we could think that a lower resolution is optimal, as it does not imply a great cost for the producer, nor does it limit the consumer. A resolution of 240p or 360p is certainly suitable for older mobiles, but offers poor image quality for larger screens, such as computers or televisions.

So what are we left with?

With the already named HD or “High Definition” format, your video will maintain a professional look and quality, while saving space, time and data. 


As you may have noticed, video content and streaming platforms are currently making a huge impact, as they are at everyone’s fingertips and are the resource that everyone turns to for a variety of reasons. This means that those who offer their work through them are trying to ensure that it stands out from the rest, that it is differentiated and positioned in a good place. 

To do this, it is necessary, in addition to the content itself meeting the needs of consumers, that its appearance as a finished product gives a very good image.

In this article, we have clarified and given an overview of the basic notions around video resolutions, the different possibilities that exist – clarifying the advantages and disadvantages and characteristics of each.

Whether your purpose in reading this article was to gain some knowledge to implement better ones in your business, or you simply wanted to get some information to better understand the labels put on TVs in the shops, we hope we have cleared up every doubt you may have, so that you will find it easy to choose the right format for your needs.

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