There are a lot of image repositories out there that are either paid or are free. I will list some of my favorites of 2018. These are the go-to image sites when I need a really good, high-definition image. All can be used commercially.
Number One on the list goes to my current favorite. And, that is Unsplash. They have over 300,000 completely free high-resolution images, which are donated by a growing number of generous photographers. It is highly suggested that the photographer be attributed for the image, which I think is more than fair. Check it out, the images are stunning!
Number Two is the staggeringly huge Getty Images. Between it and its sister site, istock.com, they have over 200 million images that are royalty-free. They do cost money to download the images, but many of these images have won awards, so there is that. So, in short, these are Paid.
At Number Three, shutterstock comes in a close second to Getty Images. They have over 165 million images and appear to be quickly catching up to Getty Images. They were started in 2003 with only the photos of its founder, but quickly grew. These are Paid.
Number Four is the lesser know (at least by me) photo repository called Pexels. Their license is Creative Commons Zero, which means they can be used for any legal purpose, including commercially. Attribution is suggested. I was unable to find the size of their repository, so I will assume that it is smaller than the others above. These images are completely free to use.
Pixabay sits very comfortably at Number Five. They have over 1.2 million images so far. Their collections include some that are not as strongly represented by some of the others, such as “health/medical”. They are also completely free to use.
This site rests firmly at Number Six. These are images that may not have been commercially available, but have since fallen into the public domain. They are completely free to use.