Creative Commons License

Operational definition

A Creative Commons (CC) license is one of a standardized, pre-written set of public copyright licenses published by the nonprofit organization Creative Commons that a rights holder can attach to a copyrighted work to grant reusers specific permissions in advance — without requiring them to ask permission or negotiate terms individually for each reuse. A work “has a Creative Commons license” when its rights holder has affirmatively applied one of the standard CC legal tools to it and marked the work accordingly (a license badge/icon, a statement in a colophon or metadata field, or a deposit-form selection in a repository or journal system). Applying a CC license does not transfer or waive copyright itself — the creator keeps copyright and grants only the specific permissions the chosen license spells out, subject to the conditions attached to it.

The four core license elements

Every standard CC license is built by combining a subset of four condition “elements,” each represented by its own icon and two-letter code:

• BY (Attribution) — the reuser must credit the creator and indicate if changes were made. Every standard CC license (all six combinations below) includes BY; there is no CC license without an attribution requirement.
• SA (ShareAlike) — adaptations of the work must be distributed under the same license as the original.
• NC (NonCommercial) — the work may be used only for purposes not primarily directed toward commercial advantage or monetary compensation.
• ND (NoDerivatives) — the work may be redistributed, but only unmodified and in whole; no adaptations may be shared.

The six standard licenses (plus CC0)

Combining those elements produces exactly six standard licenses, ordered here from most to least permissive:

1. CC BY — Attribution. The most permissive standard license: any use, including commercial use and adaptation, is allowed provided the creator is credited.
2. CC BY-SA — Attribution-ShareAlike. Same as CC BY, plus any adaptation must carry the same license.
3. CC BY-NC — Attribution-NonCommercial. Adaptation and reuse are allowed, but only for noncommercial purposes.
4. CC BY-NC-SA — Attribution-NonCommercial-ShareAlike. Noncommercial reuse and adaptation, with adaptations required to carry the same license.
5. CC BY-ND — Attribution-NoDerivatives. Redistribution of the unmodified work is allowed, including commercially, with credit; no adaptations.
6. CC BY-NC-ND — Attribution-NonCommercial-NoDerivatives. The most restrictive standard license: unmodified redistribution only, noncommercial purposes only, with credit.

Alongside the six licenses, Creative Commons also publishes CC0 (“CC Zero”), which is not technically a license at all. CC0 is a public domain dedication: the rights holder waives copyright and related/neighboring rights “to the fullest extent permitted by law,” so reusers may copy, modify, distribute, and build on the work — including commercially — without asking permission or crediting the source. Because CC0 removes rights rather than licensing them conditionally, it sits outside the BY/SA/NC/ND element system entirely.

Current version

Creative Commons has published four generations of the license suite; version 4.0, released in November 2013, is the current version and the one Creative Commons recommends for new works. This page covers the general concept, which is stable across versions, but two 4.0-specific changes are worth knowing if a work is licensed under an earlier version (2.0/2.5/3.0, still valid and still in force wherever already applied — CC licenses are irrevocable): 4.0 is “unported” and licenses database rights directly rather than requiring jurisdiction-specific ports, and it waives moral rights uniformly where legally possible. Existing works don’t need to be “upgraded” to 4.0 — a 3.0-licensed work remains validly licensed under those 3.0 terms.

How Creative Commons licenses are used in a research context

Three research-specific uses come up most often for research administrators and authors:

• Open access publishing. Most fully open access journals require a CC license on the published version of record, most commonly CC BY. Funder open access policies frequently mandate it directly — for example, Plan S requires CC BY by default for the outputs of cOAlition S-funded research, with CC BY-SA or CC0 as acceptable alternatives and CC BY-ND permitted only by exception. A journal’s or repository’s license field is how a reader (or a machine, via NISO’s Access and License Indicators) determines what reuse is actually permitted, distinct from whether the article is merely free to read.
• Research data and code sharing. Data repositories and funder data policies typically steer toward CC0 or CC BY rather than the more restrictive combinations, because raw facts and measurements are frequently not copyrightable in the first place, and NC/SA/ND conditions interact poorly with how datasets actually get reused — merged into larger compilations, subsetted, or recombined with data under other terms. See CASRAI’s guide on Creative Commons Licenses for Research Data: CC0 vs CC-BY vs CC-BY-NC for the narrower question of choosing among those specific options, and the data availability statement entry for how a license choice typically gets disclosed alongside a dataset.
• Software is the deliberate exception. Creative Commons itself recommends against applying any of the six standard CC licenses to software source code: they lack software-specific terms (source-code distribution, patent grants) and are not compatible with major free/open-source licenses such as the GPL. Creative Commons explicitly endorses CC0 for dedicating software to the public domain, but for software that should remain reusable and license-compatible, an OSI-approved or FSF-recognized open-source license is the correct tool, not a CC BY/SA/NC/ND combination. See CASRAI’s guide on Open Source Software Licensing in University Technology Transfer.

Worked examples

• A journal article published under a fully open access model, with “This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (CC BY 4.0)” stated in the article’s footer and encoded in the journal’s metadata — any reader may redistribute, translate, or reuse the article, including commercially, provided the original authors are credited.
• A research dataset deposited in a repository such as Zenodo or Dryad with a CC0 waiver selected at deposit, so downstream reusers (including those building automated harvesting or meta-analysis pipelines) can combine it with other data without attribution obligations or licensing ambiguity.

Counter-example: a journal article marked “open access” or “free to read” on a publisher’s website, with no license statement at all or a statement that reuse requires publisher permission, is not Creative Commons licensed — free access and a reuse license are two different things, and a reader cannot assume CC terms apply just because a paywall is absent.

Related terms

See also: Copyright, Copyright transfer agreement, Reuse license, RightsLink (the copyright-clearance workflow used for content that is not CC licensed), and NISO Access and License Indicators (ALI).