iNaturalist
Resource libraryA free resource library, listed under “Stock photos”, available on the web.
Completely freeWebStock photos11 resources
Free stock photo libraries, with the exact license of each: CC0, custom license or mixed licenses.
Wikimedia Commons
Resource libraryFree media library of millions of images, sounds and videos, each with its licence and author stated.
Completely freeWebGeograph Britain and Ireland
Resource libraryFree resource library for the web, listed under “Stock photos”.
Completely freeWeb
NASA
Resource libraryFree resource library for the web, listed under “Stock photos”.
Completely freeWebWP Photo Directory
Resource libraryA free resource library, listed under “Stock photos”, available on the web.
Completely freeWeb
World Register of Marine Species
Resource libraryA free resource library, listed under “Stock photos”, available on the web.
Completely freeWebAnimal Diversity Web
Resource libraryFree resource library for the web, listed under “Stock photos”.
Completely freeWebPixabay
Resource libraryFree images, videos, music and sound effects under the Pixabay content licence; some uses are restricted.
Free, with trade-offsWebPexels
Resource libraryFree stock photos and videos, usable without attribution under the Pexels licence.
Free, with trade-offsWebOpenverse
Resource librarySearch engine for hundreds of millions of openly licensed and public domain images and sounds.
Free, with trade-offsWebUnsplash
Resource libraryHigh-resolution photos free to use under the Unsplash licence, commercial use included; selling them unchanged is not allowed.
Free, with trade-offsWeb