Photogen
Photogen provides free high-resolution photographs for download and reuse. Users can search by keywords or browse by categories.
Pixabay
Pixabay is a photo community that provides images on public domain. The site contains curated images contributed by photographers around the world. As of September 2015, there are more than 470,000 photographs, vectors and illustrations. Users can search by keywords or browse by various categories.
Lock & Stock Photos
Lock & Stock Photos provides photographs taken by social media marketeer, AJ Montpetit.
PLiXS Image Database
Founded by a startup based in Switzerland, PLiXS is a database of free high resolution images. As of August 2015, there are close to 3,400 images, contributed by photographers around the world. Users can search or filter their search by photo filters and categories.
Skitterphoto
Skitterphoto provides photographs that are taken by three photographers based in Groningen, The Netherlands. Since the platform launched in 2014, a photo is uploaded every single day. Users can search or browse by categories.
Pexels
Developed by German web developers, Pexels provided handpicked stock photos from free image sources, such as Unsplash and Gratisography. To date, there are over 3,000 images that are on Creative Commons zero (CC0) license. Users can search or browse the images.
Wellcome Images
Wellcome Images is one of the visual collections of the Wellcome Library. It contains themes ranging “from medical and social history to contemporary healthcare and science”. To date, there are close to 130,000 images across different themes.
National Geographic Wallpapers
The National Geographic Society is one of the largest scientific institutions in the world, focusing on geography, archaeology, natural science, conversation and the study of world culture and history. They offer stunning photographs, which can be a good source of images in these areas for educational and personal purposes.
Albumarium
Compiled by Swiss UI designer, Vilem Ries, Albumarium offers high-resolution photographs, organised in different albums. Photographs on this site are contributed by users on Creative Common licenses.
MorgueFile
Developed by Michael Connors in 1996, MorgueFile is an online community for photographers and remains as a popular image source for creatives. It is currently managed together by Michael and his brother, Kevin Connors, and Johannes Seemann. This platform contains photographs “freely contributed by many artists to be used in creative projects by visitors to the site“.
Getty Images Embed
Getty Images is one of the world’s leading suppliers for stock images. Through their embed tool, users can drop an image into their blog, website or social media feed without worrying about copyright restrictions. The tool will generate a code that will automatically include the necessary attribution and link back to the licensing page.