“Free image” can mean four different things. Some free images need no credit at all. Some need a credit line. Some need a credit and put rules on anything you make from them.
If you use free pictures for a blog, a video or a product, these are the four labels you’ll see over and over, especially on Wikimedia Commons. Here’s what each one lets you do, in plain words.
I’m not a lawyer. This is how the licenses read and how Commons uses them, not legal advice for your situation.
TL;DR
- CC0 and public domain need no credit; for everyday use they work the same.
- CC BY needs a credit; CC BY-SA needs a credit and your changed version must use the same license.
- All four allow commercial use; check each file, because licenses vary picture by picture.
Who this is for
- Blogger: know which images you can drop in without a credit line.
- Etsy or print-on-demand seller: know which images are safe to build a product on.
- YouTuber: know what goes in the description and what doesn’t.
- Teacher: explain image licenses to students in two minutes.
- Marketing manager: set a simple rule for your team about which free images are OK.
The short version
- Public domain: Credit needed: No; Commercial use: Yes; Can you change it: Yes; Rules on your changed version: None
- CC0: Credit needed: No; Commercial use: Yes; Can you change it: Yes; Rules on your changed version: None
- CC BY: Credit needed: Yes; Commercial use: Yes; Can you change it: Yes; Rules on your changed version: Credit the original, say you changed it
- CC BY-SA: Credit needed: Yes; Commercial use: Yes; Can you change it: Yes; Rules on your changed version: Same, plus your version must be CC BY-SA
Public domain
Public domain means there’s no copyright. Nobody owns it. Usually that’s because:
- It expired. In the United States, works published before 1931 are public domain as of 2026. In many other countries, copyright ends 70 years after the author died.
- It never had copyright. In the US, work made by federal government employees as part of their job isn’t copyrighted. Most NASA photos are public domain for this reason.
You can use it any way you like, with no credit. The one catch: public domain can depend on the country. A file can be public domain in the US and still under copyright somewhere else. Commons writes the reason on each file page.
CC0
CC0 is a tool from Creative Commons. The creator says “I give up all my rights to this, as far as the law allows”. Where a country doesn’t let you give up copyright completely, CC0 falls back to a license that lets anyone do anything.
So what’s the difference between CC0 and public domain? Where it came from. Public domain is a status: the copyright is gone. CC0 is a choice: the owner gave it away. For you as a user, they work the same. No credit, no rules.
CC BY
CC BY means you can use, share, change and sell it, as long as you give credit. A credit has the title, the author, a link to the source and the license, linked. If you changed the picture, say so.
CC BY-SA
CC BY-SA is CC BY plus “share alike”. The SA part only kicks in when you change the picture itself and share your changed version.
- Using it as is in your blog post, slide or video: credit it. Your post doesn’t become CC BY-SA.
- Changing it (a recolor, text on top, a collage, a design built from it): your new version has to be shared under CC BY-SA too. That means anyone can reuse your version, with credit.
That’s why print-on-demand sellers avoid CC BY-SA. A t-shirt design built on a CC BY-SA photo would be CC BY-SA.
What about the version numbers?
You’ll see CC BY-SA 2.0, 2.5, 3.0 and 4.0. They all work the same way for everyday use. 4.0 is the newest and the same worldwide, and it says you have to mark changes. Credit whatever version the file has.
What’s not on Commons
Wikimedia Commons only accepts free files. You won’t find “non-commercial” (NC) or “no derivatives” (ND) licenses there. So the answer to “are Wikimedia Commons images free to use?” is yes, including for business, but most need a credit.
You’ll also see a few other free licenses on Commons, like the GFDL and the Free Art License. They allow commercial use too, with their own credit rules.
Copyright isn’t the only rule
Even with a public domain or CC0 picture:
- People: using a recognizable person to sell something can need their permission.
- Trademarks: a logo in the picture is still a trademark.
- Endorsement: you can’t imply the creator or an agency (like NASA) endorses you.
How to see the license on every picture
On Commons, it’s in the Licensing box on each file page. Checking 30 file pages one by one is slow, so I built Free Image Finder, a free Google Sheet that shows it for every search result.
- Make your copy and click 🖼️ Free Image Finder > Quick setup.
- Search on the Search tab. Each card in the gallery shows its license.
- The Results tab has LICENSE, CREDIT NEEDED (Yes or No) and a ready CREDIT LINE for every file.
- Want no credits at all? Set License to Public domain & CC0.
When I searched “red panda” on 2026-10-26, the top three photos were CC0, CC BY-SA 3.0 and CC BY-SA 4.0. Same subject, three different rules. That’s normal.
The Public domain & CC0 filter uses Commons’ structured data, the “license” and “copyright status” fields on each file. A few older public domain files don’t have those fields filled in yet, so they won’t show up with the filter on. They’ll still show with Any free license, marked public domain in the LICENSE column.
Common pitfalls
- Thinking “free” means “no credit”: most Commons files need a credit. Only public domain and CC0 don’t.
- Thinking CC BY-SA can’t be used commercially: it can. It just needs credit and share alike on changes.
- Building a product on CC BY-SA: your design becomes CC BY-SA. Use public domain or CC0 for products.
- Checking the site, not the file: every file on Commons has its own license.
- Forgetting the country: “public domain in the US” isn’t always public domain where you are. Read the reason on the file page.
- Ignoring people and logos: a free license covers copyright, not trademarks or the people in the shot.
Learn the Google Sheets formulas in this post
- FILTER formula: pull only the files where CREDIT NEEDED is No.
- COUNTIF formula: count how many of your saved images need a credit.
- HYPERLINK formula: link each license name to the license page.
Better Sheets has hundreds more tutorials like these. If you want to get better at Google Sheets, join Better Sheets.
FAQ
Is CC0 the same as public domain?
For using a picture, yes: no credit, no rules. The difference is how it got there. Public domain means the copyright is gone; CC0 means the owner gave it up on purpose.
Can I use CC BY-SA images commercially?
Yes. You need to give credit, and if you change the image and share your version, it has to be CC BY-SA too.
Does a CC BY-SA image make my whole blog post CC BY-SA?
No. Putting the picture in your post as is doesn’t change the license of your writing. Only changed versions of the picture itself carry the share alike rule.
Do I need to credit CC0 images?
No. A credit is optional. It’s still a nice thing to do.
Are Wikimedia Commons images free to use?
Yes, including commercially. Commons only accepts free licenses and public domain files. Most need a credit line.
How do I write the credit?
Title, author, source link and license. There’s a full walk-through with examples in how to credit an image.
Get the sheet
Free Image Finder is free. It shows the license on every picture and writes the credit for the ones that need it. All the features are on the tool page.
