To facilitate quick access to Creative Commons image resources, you might consider installing the Creative Commons Search Browser Extension. The tool adds a button to your web browser and lets you Search for Creative Commons licensed content, attribute the owner/creator with one-click attribution, and bookmark or download image resources. You can apply several useful filters to your search. The tool currently federates content from the following sources:

Flickr
Wikimedia Commons
Animal Diversity Web
Biodiversity Heritage Library
Brooklyn Museum
Cleveland Museum of Art
Culturally Authentic Pictorial Lexicon
SpaceX
DeviantArt
SVG Silh
Digitalt Museum
Thingiverse
Thorvaldsens Museum
World Register of Marine Species
Smithsonian Institution: National Air and Space Museum
Smithsonian Institution: Smithsonian American Art Museum
Smithsonian Institution: National Museum of American History
Smithsonian Institution: National Museum of the American Indian
Smithsonian Institution: Smithsonian Gardens
Smithsonian Institution: Anacostia Community Museum
New York Public Library
Europeana
Flora-On
Geograph Britain and Ireland
Metropolitan Museum of Art
McCord Museum
Museums Victoria
NASA
PhyloPic
Rawpixel
Rijksmuseum
Science Museum – UK
Sketchfab
Smithsonian Institution: Smithsonian Libraries
Smithsonian Institution: National Museum of African American History and Culture
Smithsonian Institution: National Museum of African Art
Smithsonian Institution: National Museum of Natural History
Smithsonian Institution: Cooper Hewitt, Smithsonian Design Museum
Smithsonian Institution: Freer Gallery of Art
Smithsonian Institution: Hirshhorn Museum and Sculpture Garden
Smithsonian Institution: National Portrait Gallery
Smithsonian Institution: National Postal Museum
Smithsonian Institution: National Zoo
Smithsonian Institution Archives
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