Gratisography is my personal favorite image archive. It provides you more artistic images than you can use in your projects. Many quality images are added each week and are free of copyright restrictions.
Mainly two photographers (Ryan McGuire and Bells Design) are involved in capturing the images. They have offered the pictures under Creative Commons Zero license, which means you can freely use all the pictures of their collection without providing any attribution.
Unsplash is another source of magnificent images to use for your blog. It adds 10 new images every 10 days, and also delivers them directly to your inbox. The images in this site are captured by artists from different backgrounds, so the site contains a variety of photographs.
All the images this source provides fall under Creative Commons Zero license. Once you download the image, you can use it for any purpose fromsetting up your blog to printing brochures, without worrying about who to credit.
Superfamous was designed by Folkert Gorter. You can use varieties of images from different categories such as nature, technology, and abstract. Most of the images in this collection are taken from aerial view.
This source provides images under the Creative Commons Attribution 3.0 license, which means you can use them in any way you like but you have to give the credit.
This site also contains links to other sites such as Cargocollective, which provides a collection of selected images from selected artists.
Pexels contains thousands of images and adds 10 new images each day. All the images in this site falls on the Creative Commons Zero license which allows unrestricted use of high quality images from its collection for personal and even for commercial use. You can even modify, copy and distribute the images.
In this source, most people search images under categories like summer, business, abstract and art. It guarantees to add 3600 new images each year, which makes it to be one of the biggest stock image sites.
Pixabay has a large collection of stunning images. With over 450,000 free photos, vectors, and arts illustrations, it offers you royalty free stock photos which you can use for commercial application. You don’t need to provide any attribution in digital or printed form to use Pixabay images.
This site also has the option of browsing by category. You can browse images from different categories like animals, education, backgrounds/textures, nature/landscapes, and many more.
Flickr is the biggest image hosting web platform, which provides you 1,000 GB of free storage. Flickr also has a collection of millions of free stock images. It has always been a reliable source of high quality free images.
Flickr has eight different license categories. Some are royalty free and some need credits. If you don’t want to give credit to the creator, then you can use images from ‘Free Use Photos’ section.
Stocksnap selects the highest quality, highest resolution pictures and adds to its database regularly. Users consider it to be one of the best place on internet to find beautiful free stock photos.
All the images stored in this site fall under Creative Commons Zero license and hence do not require attribution. It collects best stock photos from the web and also uploads images from selected photographers. The motto of the site is to create a community of great photographers who want to share their art with the world.
Picography is the simplest site in this list. It has no options to search or browse by category. You can simply scroll down through the gallery. It offers you random photos from great photographers. It adds new photos to its gallery on a regular basis.
All the images are provided free of charge and under the Creative Commons Public Domain CC0 license. But it doesn’t allow you to advertise the photographs as your own.
If you’re involved in web projects, then the best place to find free stock images is Freeimages. It has search options and lets you browse by category. These options can save you incredible time when you’re working. Most of the images in this site are of textures and backgrounds.
Three different forms of right are granted by the site: perpetual, non-exclusive and unlimited. You can use any image to copy, reproduce, modify, edit, display and publish in your work.
Picjumbo is the latest free stock image site. It offers you high quality free images as well as a premium membership option. New images are added on a daily basis. So, you can check this site regularly to find images you may like. You can use a Picjumbo image for commericial use, HTML/PSD/PowerPoint templates and also print them on T-shirts.
The main drawback of this site is that it is an ad-funded site, so the ads may distract you.
Great article by Lifehack, a great source of resources!