A short guide to public-domain photography

A work in the public domain is not owned by anyone — its copyright has expired, was never granted, or was deliberately waived. Anyone can use it for any purpose without permission or payment. For photography, the most common route is age: after a long enough period (which varies by country), copyright lapses and older photographs enter the public domain. That's why archives are so rich in nineteenth- and early-twentieth-century images.

Not every free image is old. Many modern photographers release their work under Creative Commons licenses, which grant reuse rights while keeping some conditions:

• CC0 — the creator waives all rights; effectively public domain.
• CC BY — free to use if you credit the creator.
• CC BY-SA — free to use with credit, if you share adaptations under the same license.

When Where only uses images under public-domain or these permissive licenses, and it always shows the credit.

Two collections do most of the heavy lifting for open imagery. Wikimedia Commons holds tens of millions of freely-licensed media files, many geotagged and dated. The Met's Open Access program released hundreds of thousands of images under CC0. Between them they cover more than a century of photography from around the world.

Even when a license doesn't strictly require it, crediting the photographer is good practice — and often legally required under CC BY and CC BY-SA. Check each file's stated license rather than assuming, and keep the attribution with the image. That's exactly what happens on every When Where reveal. Read more about our image sources or go play a round.