What is a JPEG? The internet’s most popular image format explained

Everything you need to know about the image format, and how it can help save space when filing away photos.

You’ve probably got quite a few files that end with .jpg or .jpeg on your computer. These are known as JPEGs (pronounced jay-pegs), a type of image that’s optimised and compressed for use on the internet.

But what does JPEG stand for? Why is a JPEG better than other image file types? And what makes it so good for use on the web? Find out all this and more in our handy guide.

[Read more: How to share your photos with BT Cloud]

What is a JPEG?

A JPEG is a type of image commonly found on the internet. The term refers to a type of compression that makes image files much smaller than the ‘RAW’ files that are taken by high-end digital cameras.

What does JPEG stand for?

JPEG stands for Joint Photographic Experts Group. This is the group that created the JPEG compression standard.

Why is a JPEG better than a RAW file?

JPEGs are much smaller than RAW files, which means they’re easier to email to friends and to upload to websites and social media sites. RAW files are only really useful if you’re printing the photos out at a large size, because they contain so much detail that most of it will be lost when viewed on a computer screen or printed at a small size.

Which programmes open JPEG files?

Most image programmes open JPEG files. The most commonly used is Microsoft Windows Photos, which is the default programme that comes preinstalled on Microsoft PCs. You can also open JPEGs using paid-for graphics programmes like Adobe Photoshop, but these can be expensive and confusing to use. Most web browsers can also open JPEGs.

When was the JPEG created?

The group responsible for the format was formed in 1986. The format was submitted and approved in 1992, so it’s been around since the early days of the internet.

When shouldn’t you use a JPEG?

Most digital cameras automatically save your photos as JPEGs, as do most graphics programmes. However, if you’re creating a line drawing or other graphic involving textual/iconic graphics, you might be better off saving it as another file format, such as TIFF, GIF, PNG or RAW. That’s because graphics like these typically have sharp contrast between the pixels, which can cause some graininess in the image if it’s saved as a JPEG. This can be avoided with a ‘lossless’ file format, like those listed above.

How can you identify a JPEG?

It will have the filename extension .jpg or .jpeg. In other words, if you’ve named a photo ‘landscape’, the file will appear on your desktop as ‘landscape.jpeg’. JPEGs can also take the filename extensions .jpe and .jfif, although these are less common.

[Read more: Struggling to open a document or photo? Here’s how to do it]

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