1. Morguefile
one of the oldest free high-quality stock photo sites, and it has a lot of images (more than 350,000, as they state).
2. Pixabay
It’s even better than Morguefile. This site offers over 740,000 stock photos, vectors, art illustrations, and videos, and the best is all of them are licensed under the Creative Commons CC0 license. This means you may download, modify, distribute, and use them royalty free in any project you like, including commercial projects.
3. Pexels
This is another big site with hundreds of thousands of free high-quality stock photos. Every day 100 new high quality photos are added, so the collection is always growing. As for licenses, it’s again CC0, which means the photos are free to use for any legal purpose with no need to ask permission from the author or to make attribution. One of the nice features of the site is that you can search for images by color.
4. Flickr
Flickr is a place to upload your photos, but you might not know that it’s also one of the largest repositories of free high-quality stock photos. Many users opt to license their photos under a free license. However, be careful because not everything on Flickr is copyright free.
5. Free Images
Free Images is a site where you can find images you don’t have to pay for. This site has a ton of images (almost 400K photos and illustrations) in many niches, though not all of the photos are high quality. Additionally, some of the photos are restricted by a license, so check carefully before you use a photo, especially in a commercial project.
6. Wikimedia Commons
https://commons.wikimedia.org/wiki/Main_Page
with its 33 million images, is probably the largest repository of free images. However, they do require attribution, which in some cases (e.g. the client you need the photo for objects to attribution) isn’t an option. They have images in any niche imaginable, but not all of them are high quality. There are also many small size images with somewhat limited practical use.
7. Unsplash
another very popular site for free high-quality stock photos. Its images are licensed under the CC0 license and there are a lot of them. What I really like about this site is its minimal and clean interface.
8. Free Digital Photos
http://www.freedigitalphotos.net
This is an old and established site with a ton of free and premium images across many categories. Unfortunately, generally only the smaller sizes are free, and some of them require attribution.
9. New Old Stock
This site is different from the rest because it’s a niche one. New Old Stock specializes in free vintage photos. If you are into old stuff, you can find real gems here. It doesn’t have a search functionality, and the photos are hosted on other sites, but still it’s a nice collection of unique vintage photos from all over the Web.
10. Picjumbo
offers both free and premium membership. Quite naturally, the paid membership offers more, but even their free section is more than suitable. There are images in many categories, and new free photos are added regularly. One of the unique features of Picjumbo is that it has aPhotoshop and Sketch plugin ($7.99), too.