Direct comparison
CC0 vs. Public Domain: The Difference
CC0 is a legal waiver reaching public-domain-equivalent status; genuine public domain arises automatically when copyright expires or never applied.
Side-by-side comparison
| Dimension | CC0 | Public Domain |
|---|---|---|
| What it is | A legal dedication/waiver tool a rights holder applies | A legal status a work has or falls into |
| How it arises | Rights holder actively applies it to their own eligible work | Copyright term expires, or the work was never copyrightable |
| Applies to works still under copyright? | Yes — that is exactly what it dedicates | No — by definition, a public domain work is not (or no longer) under copyright |
| Who acts | The rights holder, by applying the CC0 deed | No one — it happens automatically by operation of law |
| Cross-jurisdiction reliability | Designed for it — waiver plus an automatic fallback license if the waiver fails somewhere | Uneven — term length and eligibility rules differ by country |
| Typical trigger | A creator or institution’s decision (e.g. dataset release, open-data policy) | Copyright term expiry (e.g. Public Domain Day) or statutory exclusion (e.g. US federal government works) |
| Revocable? | No — irrevocable once applied | N/A — not a grant, so there is nothing to revoke |
| Related/neighboring & database rights | Explicitly waived alongside copyright | Governed independently — e.g. EU database rights can outlast the underlying copyright |
| Attribution legally required? | No | No |
| Typical use on new research outputs | Common — e.g. OpenAlex’s full catalog, optional on figshare/Zenodo datasets | Rare — almost no newly created research is old enough to have expired copyright |
| Labeling a work already believed public domain | Not the right tool — CC0 dedicates works still under copyright | Creative Commons’ Public Domain Mark (PDM) is the labeling tool for this, distinct from CC0 |
Common questions
FAQ
Is CC0 legally the same thing as public domain?+
No, though the practical reuse rights end up nearly identical. CC0 is a rights holder’s voluntary waiver applied to a work that is still under copyright. Genuine public domain status arises automatically, without anyone acting, when copyright expires or never applied.
Why not just write "this work is public domain" instead of using CC0?+
An informal public-domain declaration isn’t reliably enforceable everywhere — some jurisdictions limit how far copyright (particularly moral rights) can be renounced by simple statement. CC0 is a specifically drafted legal instrument, with a waiver plus an automatic fallback license, designed to hold up as consistently as possible across different legal systems.
Does CC0 require attribution?+
No, not legally. Researchers commonly cite CC0 material anyway as a matter of scholarly citation norms, but CC0 itself imposes no attribution condition, unlike CC BY.
Should I use CC0 to release a research dataset?+
It is one of the most common choices for exactly that purpose. Because even an attribution-only condition can complicate merging datasets from multiple sources, many repositories offer CC0 alongside CC BY, and some open infrastructure projects (OpenAlex’s full metadata catalog, for example) use CC0 by default.
What is the difference between CC0 and the Public Domain Mark (PDM)?+
CC0 actively dedicates a work that is currently under copyright. PDM simply labels a work already believed to be in the public domain (typically historical material with expired copyright) — there is nothing left to waive, so PDM is a label, not a legal act.
Going deeper
