Finding images for a presentation, a blog post, a paper figure, or a website is easy. Finding images you are actually allowed to use — without worrying about copyright, licensing fees, or takedown notices — is a different problem. This post is about the latter.
Open licensing does not mean low quality. The resources below include photographs, illustrations, scientific diagrams, historical documents, and artwork from some of the world’s leading institutions. All of it is freely available under licenses that let you use, share, and in many cases modify the material.
What Counts as an Open License?
Before diving in, it helps to know what you are looking for. The most common open image licenses are issued by Creative Commons (CC):
- CC0 — No rights reserved. You can do anything with it, including commercial use, with no attribution required. The closest thing to public domain.
- CC BY — Attribution required, but otherwise free to use, modify, and redistribute.
- CC BY-SA — Attribution required; derivatives must carry the same license.
- CC BY-NC — Attribution required; no commercial use.
- CC BY-ND — Attribution required; no modifications allowed.
For research and educational use, CC0 and CC BY are the most permissive and generally the most useful. Always check the specific license on any image before use.
Five Resources Worth Bookmarking
1. Openverse
Openverse is a search engine for openly licensed media maintained by the WordPress Foundation. It indexes over 800 million images and audio files from sources across the web, including Flickr, Wikimedia Commons, the Metropolitan Museum of Art, and many more. You can filter by license type, image type, and source. It is the single best starting point if you want to search across many collections at once.
2. Wikimedia Commons
Wikimedia Commons is the media repository behind Wikipedia — a collection of over 100 million freely usable images, audio, and video files contributed by people around the world. It includes photographs, maps, diagrams, historical images, and scientific illustrations. Most content is CC-licensed or in the public domain. Every file includes a clear license statement and attribution information.
3. The Metropolitan Museum of Art Open Access
The Met has released over 490,000 images of public domain artworks from its collection under CC0 — meaning you can use them for any purpose, commercial or non-commercial, with no attribution required. The collection spans 5,000 years of art history and includes paintings, sculptures, textiles, photographs, and artifacts from cultures around the world. Images are available in high resolution through the Met’s collection portal.
4. NASA Image and Video Library
NASA content — photographs, video, audio, and data — is in the public domain by default, as it is produced by a U.S. federal government agency. The NASA Image and Video Library contains over 140,000 items: spacecraft imagery, Earth observation photos, astronaut portraits, mission footage, and historical archives going back to the earliest days of the space program. Freely usable for any purpose with attribution to NASA.
5. Unsplash
Unsplash operates under its own open license that permits free use of photos for commercial and non-commercial purposes without attribution (though attribution is appreciated). It hosts over three million high-resolution photographs contributed by photographers worldwide. The focus is on modern, high-quality photography — landscapes, people, architecture, technology, and more. Note that the Unsplash License is not a standard Creative Commons license, so read the terms before using images in contexts with specific licensing requirements.
Honorable Mentions
- Flickr Commons — publicly held photography collections from museums, libraries, and archives worldwide, all with no known copyright restrictions
- The New York Public Library Digital Collections — over 900,000 items in the public domain, freely downloadable in high resolution
- Europeana — millions of digitized cultural heritage items from European museums, libraries, and archives, with extensive CC-licensed content
- Internet Archive — a vast repository of digitized books, images, audio, and video, much of it in the public domain or openly licensed
A Note for Research Use
When using images in publications, posters, or grant materials, always:
- Verify the specific license on the image (not just the platform’s general policy)
- Follow the attribution requirements — even CC0 images benefit from a note of where they came from
- Check whether the image depicts identifiable people and whether consent or model releases were obtained
- Keep a record of where you found the image and what license applied at the time of download
Open images make science communication easier, more accessible, and more honest. Use them generously — and give credit where it is due.