Whether you’re saving images for print or web, it can be tough to know exactly which filetype is the best to use. That’s especially true if you’re trying to save space with file size. 

JPEG is the most popular format for photos on websites and apps. However, many JPEG files don’t use optimal compression, wasting valuable bytes. And if you’re saving images as the wrong type, you could end up blurring a beautiful photo, losing all the detail of your logo, or turning a transparent background white.

This is why Who Is Hosting This has created the following infographic that lets us know exactly which file type is the best. While it’s easy enough to keep all your files as they are and upgrade your storage space later, when you’re dealing with saving images for online there are a lot of factors to consider. For example, large files don’t just take up space; they also take up bandwidth and increase download times. And if the important images on your website aren’t loading fast enough for your visitors, that’s going to impact their patience and your bottom line.

So, if you want to know which file type to use for which types images—and maintaining a quality image—check out the handy infographic below.

Know your file types: When to use JPEG, GIF and PNG

JPEG

JPEG (also JPG) stands for Joint Photographic Experts Group and uses a very complex compression algorithm. They can display millions of colours and is the standard file format for most digital cameras. Use JPEG when a small file size is more important than higher quality. It’s best uses are:

• Still images
• Real-world images, like photos
• For complex colouring
• Shading of light and dark

GIF

GIF stands for Graphics Interchange Format. And while there’s plenty of public debate over whether it’s pronounced “gif” or “jif”, its creator Steve Wilhite claims it to be “jif”. This format uses up to 256 indexed colours and allows for single-bit transparency. Fewer colours means that saving images in GIF are smaller than JPEG. These files can also be animated and its best uses are:

• Web graphics with fewer colours
• Small icons
• Animations
• Simple images, such as line drawings or cartoons

PNG

It was designed in the 1990s as a way around patent issues around the GIF format and stands for Portable Network Graphics. PNG files allow for saving images with transparency set on a scale between opaque and completely transparent. They can also be placed on any colour background and still maintain their original appearance. They’re best used as:

• Web images such as logos that involve transparency and fading
• Images in the middle of the editing process
• Complex images like photographs if file size is not an issue

There are two types of PNG:

1. PNG-8: Very similar to GIF, using 256 colours and 1-bit transparency. However, the files are even smaller than GIF.
2. PNG-24: Uses 24-bit colour similar to JPEG and can include up to 16 million colours. But its lossless compression means it’s larger than most JPEGs.

With a variety of image file formats available, you can use the right format for your images to save quality and space on your website—and in your emails.

Source: http://www.whoishostingthis.com/blog/2014/12/06/jpeg-gif-png/