Center for Learning Experimentation, Application, and Research

Usable Works

Last Updated: 8/6/2023 7:55

This page contains a library of links to web site repositories for open access or Creative Commons licensed content. Much of what these web sites contain is freely available, with minimal restrictions. Go to the CLEAR Creative Commons web page to learn more about CC licensing and their requirements.

Works in Multiple Formats


  • Project Gutenberg

    A collection of public domain electronic books.


    29,000 free eBooks available for Kindle, Nook, iPad, and most other eReaders.

  • Merlot

    A free and open peer reviewed collection of online teaching and learning materials and faculty-developed services contributed and used by an international education community.




Screen capture of the Pixabay web site showing a top row of advertisement images for, followed by a list of free images below.Please Note: Some of these free image web sites generate revenue by advertising commercial 'stock' (i.e., NOT free) images within their search results. Please click the thumbnail image to the right to see an example of this in practice on the Pixabay web site.

  • All of the web sites listed directly above host images which are free and unrestricted, even for commercial use. They also do not require any kind of attribution or caption.

  • Wikimedia Commons

    Please use Wikimedia Commons with caution. Since the public contributes to a wiki with minimal editorial oversight, many of the millions of media contained within are licensed under a variety of licenses (most commonly CC BY-SA).  At times, contributors also make unauthorized uploads of media copyrighted by third parties. It can still be a useful resource, but due diligence in verifying the original authorship of an image by performing a reverse image search is always a good idea. A best practice is to use a caption with a link to the image on the site, and/or create a resource page that you have as a reference tool. 

  • Wellcome Images Library

    Over 100,000 high-resolution historical images including manuscripts, paintings, etchings, early photography, and advertisements are freely available under the Creative Commons Attribution (CC-BY) license, with an acknowledgment of the original source.

  • Max Pixel

    Like the web sites above, Max Pixel hosts images that are free and unrestricted, even for commercial use. However, some of the images require an attribution caption. Be sure to check the license terms on the right side of each page displaying an image.

  • PublicDomainVectors (Clip Art)

    This web site offers clip art that is completely unrestricted in use.

  • NASA Image and Video Library

    All of NASA's images are in the public domain.

  • Smithsonian Open Access

    The Smithsonian Institute has released nearly 3 million 2D and 3D digital items from their collections—with many more to come—under the Creative Commons Zero (CC0) public domain license.  You can download, share, and reuse them however you wish.

  • Flickr - Creative Commons Licensed & Public Domain Works

    Please proceed with caution when browsing the Flickr web site. Flickr hosts a variety of photographs, but some of them are copyright protected and highly restricted, so please review the license terms before using any photograph or image from Flickr. To help you with this process, we are providing the link above, which is to a special page on Flickr that provides a jump-off point for access to all the Creative Commons licensed and public domain works on their site. If you follow the above link and click one of the "see more" links, it will then give you an option to search images which are licensed or unlicensed according to that group.

  • New York Times — Public Domain Images Archives

    Via Wikimedia Commons

  • National Gallery of Art

    The NGA has an open access policy for digital images of works of art believed to be in the public domain. Images are free of charge for any use, and users do not need to seek permission.

  • The British Library

    Over a million images on Flickr Commons for anyone to use.

  • Andrew McMeel Syndicated Comics

    McMeel grants educators permission to use select comics in their instructional materials. Among their syndication's clients are Peanuts, Garfield, Close to Home, Dilbert, Pearls Before Swine, Off the Mark, Foxtrot, Marmaduke, Non Sequitur, Doonesbury, Ziggy, and more!  PLEASE NOTE: Although Calvin & Hobbes are part of McMeel's line-up, they are NOT allowed to be copied for educational purposes. They are the only exception to McMeel's grant of permission.

  • xkcd by Randall Monroe

    All xkcd comics are licensed under the Creative Commons Attribution-NonCommercial 2.5 License. In the creator's words, it means "you're free to copy and share these comics (but not to sell them)." However, they do require the inclusion of a CC attribution caption.

  • Bizarro by Dan Piraro

    In his FAQ page, Dan Piraro grants educators permission to use his comics during their course of their instruction, but not in any publication or service that is for-profit.  If you use one of his comics, he asks for a small donation so he can continue plying his trade.

  • Savage Chickens

    Dan Savage, the creator and owner of the Savage Chickens comic strip was kind enough to email us and tell us that we are free to use his comic strips as part of the instruction in any course, but he requests a link in a caption back to his web site in return. Also, if you would like to use one of his comics in a publication or in any other context, please reach out to him for pricing information.

  • Harvard Law School: Finding Public Domain & Creative Commons Media

    This resource provides a list of additional web sites and ways to search them for public domain and free-to-use assets.