Here are some sites that I look for Free Stock Images, Vector Graphic, Icons.
Free Stock Images
Unsplash
Best among others, the FREE Images are very very good quality, even better than some paid site. It’s my number 1. Number of the image is in vertical format
pixabay
Here is second place I search for images, there are over 1.5 million royalty free stock photos and videos shared by the generous community.
pexels
Best among others, the FREE Images are very very good quality, even better than some paid site. It’s my number 1.
Freepik
You may find some image and vector graphic here, some of the vectors are actually not bad.
Pikwizard
Over 100,000 completely free images on the site, over 20,000 of those are exclusive to us. They are also adding new images to our library daily and our ultimate goal is to get to more than 1 million images.
Photo by Iñaki del Olmo on Unsplash