Images: Public Domain and Openly Licensed

Pixabay has over 1.8 million royalty free, high quality images, including photos, illustrations and vector graphics.  Images are free to use and modify, even for commercial purposes via the identical CC0 license.

NOTE: Pixabay does not permit users to sell unaltered copies of its images; also limits how its images of recognizable people's faces or brands may be used.

The Pixabay license allows for almost any use of its images for free, including for commercial or non-commercial purposes; modifications permitted. Attribution is not required, though it is appreciated.

License information

Unsplash has a photograph collection of more than 500,000 images. All images are free to use, even for commercial purposes.

NOTE: Unsplash does have some limits to how its images of recognizable people's faces, trademarks or brands may be used.  For details see the FAQ.

The Unsplash licence allows for almost any use of its images for free, including for commercial or non-commercial purposes; modifications permitted. Attribution is not required, though it is appreciated.

License information. 

For details of how images of recognizable faces, trademarks or brands are limited see the FAQ.

A collection of public domain and freely-licensed educational media content (images, sound and video clips). For permissions info, see the Simple media reuse guide.

NOTE: these are not available via a blanket Creative Commons license - each image will have clearly detailed information about the specific CC license terms by which it has been made available.

All versions of CC licenses are represented. Check individual images for license information. 

For more details on permitted uses see about Creative Commons Licenses.

Flickr's own Creative Commons search - searching within its own collections only.  Results are based on the license conditions offered by the Flickr user who uploaded the content. 

NOTE: This search service does not search across license terms - each CC license type has a clearly labelled, separate search engine - click the "See More" link under each listed CC license to begin searching that pool of images.

All versions of CC licenses are represented. Check individual images for license information. 

For more details on permitted uses see about Creative Commons Licenses.

Hosted by the National Museum of Natural History from the Smithsonian, this project seeks to provide "global access to knowledge about life on Earth."  Encyclopedia entries include image(s) shared under different licenses - though most are published under Creative Commons licenses.

Over 51,000 open access digital images from the US National Gallery of Art, with many famous works included. NGA's Open Access Policy encourages wide use and provides details on permissions.

Open access, free of charge for any use, commercial or non-commercial. 

License information.

"A collection of icons, the Noun Project strives to build a global visual language that everyone can understand."

Icons have public domain or creative commons licenses; however the site's Terms & Conditions require that all users who do not have a paid account must provide an attribution for each image, each time it is used, in addition to adhering to any other license conditions that may apply.

Icons can be used for free with mandatory attribution. Paid account holders have access to the identical collections, but are not required to provide attributions, may download icons in colour and have access to all the service's apps.

Creating an account with NounProject is required for both paid and unpaid users.

Terms of use. 

Most of the images in this searchable database are in the public domain; those that are not specify permitted uses and attribution.

Under 'Advanced Search' you can filter by 'Usage Rights' to only show search results published under an open license. For example, "free to use share or modify"

NOTE: This search feature identifies images based on how the images are labelled - but does not verify that the images were uploaded by the rights' holder, nor that they appear on a given website with the rights' holder(s) knowledge or permission. The onus is on the user to make these verifications prior to using another person's work.

From the Creative Commons site: a very useful search engine "that allows openly licensed and public domain works (from the Internet) to be discovered and used by everyone."  Search filters allow you to filter by specific CC license; the Use filter allows you to see results that permit commercial use and/or "modifications permitted."

NOTE: this search service provides results from outside of the Wikimedia Commons. The onus is on the user to verify license conditions and that the image has been made available with the rights' holder's permission/knowledge.

All versions of CC licenses are represented. Check individual images for license information 

For more details on permitted uses see about Creative Commons Licenses.

All photos on the website have a CC BY NC SA license. 

For more details, see about License Information