JPG vs PNG
By Justine Mancini
What is our internet experience if not for images? Anyone who has saved an image from the web or for a simple paint program knows that there are tons of file formats to choose from.
If you’re not a graphic designer, artist, or photographer, many of those file formats aren’t going to be any of your concern. Instead, you probably most often deal with JPGs (or JPEGs) and PNGs. But do you sometimes wonder if you should use one over the other? For the most part, both are perfectly acceptable for almost any instance, but there are some differences that may matter to you. Let’s break them down a bit.
The most basic difference between the two formats is that JPG (or JPEG) has “lossy” compression and PNG has “lossless” compression. Image compression is a type of data compression applied to digital images, to reduce their cost for storage or transmission. Lossless compression means the image quality will be the same before and after compression. So with a PNG, your before and after are always the same.
You might think that PNG is always the way to go after hearing this, but that’s not necessarily true! While it’s correct that PNG will give you the highest quality, that doesn’t mean that JPGs aren’t useful. Oftentimes, JPGs are actually a great choice for websites, because the lossy compression will reduce the amount of data needed to load a photo and will help the website load faster! However, if the image in question is textually dense, has line drawing, or sharp contrast between adjacent pixels, you may do better with lossless format, even on your website.
If you need an image with a transparent background, PNG is the way to go. (PNGs are great for logos!)
Off the web, PNGs were originally designed for internet viewing rather than printing and can be palette-based, grayscale, and full-color non-palette-based RGB/RGBA. So if you are using CMYK color, a JPG will be your better bet for print. (Source: undsgn.com)
In short, there are really very few noticeable differences between JPGs and PNGs to most people, but sometimes the little differences matter. The most common practice, though it can vary per situation, is to use JPG for photographs and PNGs for graphics. Again, both have pros and cons with little noticeable differences in most instances, so consider your own specific situation before choosing your file type!