If you’ve spent any amount of time on a computer, you’ve likely encountered a number of different image file formats. Some are easy to work with and do what you want, and some pose problems because they aren’t formatted for what you are trying to do. Believe it or not, each image type has an intended purpose that it is best used for. Knowing which file types to use will not only make your work a lot easier, but it will likely give you better quality images.
JPEG – Joint Photographic Experts Group
JPEG is the most commonly used file format because cameras and websites can both read it easily. It also compresses images so that there is less power and time required to open the image and less space taken up by it. The only downside to this compression is that it degrades the quality of the images, and every time you edit and save a JPEG it looses some quality. This compression also makes text and lines look pixelated.
Pros: Very widely used, highly compatible, easily compressed, great colour quality
Cons: Looses quality when compressed, discards a lot of data, can’t be transparent, makes text and lines look pixelated
When to use: In general, you should use JPEGs when small file size is more important the maximum image quality. For example, on websites – since you want to save space in your database and the image you’re displaying doesn’t need to be huge. *You do not want to use a JPEG for a logo or line drawing, because the compression makes lines look jagged and unclear.
TIFF – Tagged Image File Format
TIFF is generally the best file format for commercial use because it is versatile and will not loose quality or degrade when you save it. Tiffs are also very flexible in terms of colours because there is no limit to the number of colours they can use. The only problem is that Tiffs can not be displayed on webpages, but since you need smaller sized files for online use, you wouldn’t want to use TIFFs anyways.
Pros: Great image quality, supported by many design programs
Cons: Not widely web compatible, large file size, long loading time
When to use: If you are printing out flyers with a photograph on them or something along those lines, Tiff would be the best file choice to maintain image quality.
PNG – Portable Network Graphics
PNGs were designed specifically for the web, and are a widely accepted file format because they maintain image quality. They are also useful because they can be saved with transparent backgrounds. So if you had an image like a custom Pin it Button that you need to place over another and you didn’t want to see any white space in the background, this would be the file format to use. PNGs are like JPEGs in that they keep the colours and quality of images, but they also make lines and text look better, so would be better suited for a logo.
Pros: mostly web compatible, doesn’t loose quality, smaller file sizes than TIFF, maintains quality of text and lines
Cons: can’t be animated, larger file size than JPEG,
When to use: You can use this for images online if you are looking for a transparent background, or if you have an image with text or line art.
GIF – Graphics Interchange Format
GIFS are able to compress images like JPEGS, but without degrading or losing any quality. But they are only able to use a certain number of colours. This means images that you design yourself with only a few different colour codes can be saved well in GIFS, but a photograph with thousands of different colours would be degraded in GIF format. GIFs can also be animated, which is likely the format that you are familiar with them in.
Pros: Great colour resolution on images with few colours, small file size, can be animated, can be transparent
Cons: Poor colour resolution on images with many colours (photos), very old file type
When to use: You can use gifs when you have an image that is animated, or on a file that doesn’t have many colours.
Of course, there are more than just four image formats out there, but these are the ones that you are most likely to encounter and use when online. For the most part, if you are running a blog or a website you are safe using JPEGs for most of your images. The only times you would need a better quality file is if you are planning to let your users open, download, or print the file in a large size – in which case TIFF is probably your best bet (though remember, it will take more space and more time to load). You also need better quality files for things like your header or feature images that might have text and lines (in which case you should use a PNG). I use PNGs for all of my feature images because I find that the text in JPEGs doesn’t look great once uploaded. But as long as you know what image type you are using (and why you are using it) you will be fine with any of the above. Just remember their pros and cons, and make sure you are always using the best option for your task.