Stock images can be useful for you in many ways, either as a blogger, web designer, video editor, photographer or even for just social networks updates alone. I have make a research on the the top free stock images sites.
You can use these images on any work as they come with zero licence and creative common licence CC0
Pixabay has over 1.3 million images and videos all for frees with a very high qualities that you can use for your footage of even content images.
Get free illustrations, vector graphics and real photos on pixabay
Pexels has uncountable numbers of free images which can be used for any creative project. You can use their images in prints, online media, offline and even in videos.
Download a higher resolution images from Pexels all for free without registrations or even through apps for Photoshop, Chrome, MS Office and all the images can be reused at anytime you want to use them.
Giving attributions to their images is not compulsory, they all have creative common licence.
StockSnap is a database of thousands of stock images snapped by top photographers and with a nice categories and latest search updates.
No registration is needed to use their website and there is a 10 free stock images for using thier Adobe Illustrator plugin.
Need full HD images? Then unsplash is the best place ti get the images that you need.
Unsplash API helps developers to integrate images into their project directly from Unsplash database
Makerstock houses over 30 stock images website where your search can bring images related the search from.
Free high-resolution pictures you can use on your personal and commercial projects, free of copyright restrictions.
ISO REPUBLIC Free Stock Photos for Creative Professionals with creative common licence