With so many file formats available for images – JPEG, PNG, GIF, and many others – how do we marketers choose the right one?
Of course, each format comes with variations in size, compression, and file quality. To make things even more confusing, the support for specific file types can also vary between email clients. In this post we will weigh the pros and cons of four popular formats for emails: JPEG, GIF, and PNG.
JPEG images (abbreviation of Joint Photographic Experts Group) are “full-color images that dedicate at least 24 bits of memory per pixel and therefore create images that can have up to 16.8 million colors”, and are often recognizable by their extension, JPG.
JPEG files retain all color information, but compress the size of the document by selectively removing data, and this compression can cause a loss in quality. In most graphics software, you can choose the degree of compression that you want to apply to individual images: clearly the higher the compression, the worse the image quality will be.
So we can say that the JPG format is perfect for images that contain many colors, but is not good for images that must only have text.
What we can suggest is that the JPG images we use in newsletters should have a quality ranging from 50% to 70%, and not higher.
GIF stands for “Graphics Interchange Format” and is “one of the file formats used to display indexed-color graphics and images in HTML documents on the web.” This means that GIF images are suitable for logos, text, or any images that do not have many colors (such as photos).
One of the main advantages of a gif image is that you can manage transparency within them: this means that you can use graphics software to erase portions of the image and turn them into transparent ones. This makes it possible to put a gif on a colored background, or even a photograph, without seeing a border around the image.
However, GIF transparency is not selective. This means that if you make a color transparent, the color will become transparent in the entire image.
Another peculiarity is the use of GIF images to support animation. Take this GIF image created by our customer Dolce & Gabbana
PNG stands for “Portable Network Graphics”, and offers a wide range of attractive features including “a full range of color depth, support for sophisticated image transparency, better interlacing, and automatic corrections for gamma monitor displays.” PNG images can also contain a brief description of the image content, which allows internet search engines to search for images based on these embedded text descriptions.
There are two types of PNG formats: PNG-8 and PNG-24. The PNG-8 format is similar to gifs in that they are saved with a maximum of 256 colors. The PNG-24 format can display millions of colors, but also comes with a larger file size. The choice will always be made according to your needs.
PNG images can reproduce background images without jagged edges, and can also be used for photographs. We must always remember that PNG images, unlike JPG images, are larger because they use “lossless” compression technology.
PNG images are not supported by older versions of Lotus Notes, nor do they support moving images.
Which format is best?
Unfortunately, dear marketers, there is no right answer to this question. We have to decide which format is the most appropriate for our newsletters and the type of communication we want to implement. Of course, if you are thinking of adding animation to your newsletter, the best format is GIF. If you need colorful and captivating images, the best format is surely JPEG with 60% quality.