Choosing a licence

Pick a license by deciding one thing: do you need to block commercial use, or block adaptations, or both? Every Creative Commons 4.0 license requires attribution. That part is settled. The rest turns on two conditions and how they combine. Confirm you hold all rights in the work before you apply any CC tool, then apply version 4.0 unless you have an informed reason to use an older port. Copyright exceptions such as fair use and fair dealing operate independently; no CC license restricts them.

The six licenses and two public-domain tools turn a wish to share into a machine-readable, legally repeatable permission. Which one fits depends on a short list of what you want to allow and what you want to block. The official license terms at creativecommons.org sort them by four conditions: BY (attribution), SA (share alike), NC (noncommercial) and ND (no derivatives). Read the exact license page before you choose, not a summary. The deed page names the conditions; the legal code, linked from the same deed, is what a court would read.

Route By Intent, Not By License Name

If you want the widest possible distribution and reuse, including commercial use and adaptations, start at the guide that answers "I want people to use my work however they want, as long as they credit me." That is CC BY 4.0. If you want to require that anyone who adapts and shares your work keeps the same open terms, that guide covers CC BY-SA 4.0. If commercial use worries you, the NC condition guides explain how version 4.0 defines it: not primarily intended for or directed toward commercial advantage or monetary compensation. The identity of the user does not decide the issue by itself. When your planned use carries material commercial risk, get separate permission or local legal advice before relying on the NC condition.

If you want to prevent any sharing of adaptations, the ND guide tells you that sharing adapted material under an ND license is not permitted. Format-shifting alone does not create adapted material under the 4.0 definition. Translation normally does. Music synchronisation with a moving image is expressly adapted material. Whether cropping, excerpting, or editing creates an adaptation depends on applicable copyright law; there is no universal boundary.

What The Individual Guides Deliver

Each guide owns the detail for its route. The trade-offs are real. ShareAlike is not a universal key. Two SA licenses are not automatically compatible. The official compatibility list from Creative Commons controls, and it currently lists one-way compatibility from CC BY-SA 4.0 to GPLv3 for adapted material. That does not turn a CC license into a software license or create compatibility in reverse.

Three properties separate these tools from a custom license or from placing no license at all.

Reach: What The License Covers

A CC 4.0 license grants worldwide, royalty-free, non-sublicensable, non-exclusive, irrevocable permission for the term of the licensed copyright and similar rights. It applies only where copyright or similar rights require permission. Exceptions such as fair use or fair dealing operate separately; if an exception authorises the use, the license conditions do not apply to that use. Version 4.0 expressly addresses sui generis database rights. It does not license patent or trademark rights. Moral, privacy and personality rights are handled only to the limited extent stated in the legal code and may still matter. Possession of a CC-licensed copy is not a guarantee that the uploader owned all necessary rights or that every component is covered.

Compatibility: Which Licenses Work Together

Combining works under different CC licenses is not automatically lawful because each input uses its own license. ND may block sharing the combination if it is an adaptation. SA may require a specific adapter's license. Two inputs can impose incompatible terms. Use the official compatibility chart from Creative Commons and distinguish mere aggregation from an integrated adaptation. A collection keeps separate works separate, such as unchanged essays in an anthology. Each work retains its own license; the collection's overall license does not replace those licenses. Adapted Material is based on and modifies the licensed work in a way requiring copyright permission. Only the contribution made by the adapter is covered by the adapter's license; notices for the original must remain.

Reversibility: What You Cannot Take Back

Once you have applied a CC license and someone has received the work in compliance with its terms, you cannot withdraw the license from that person. The license is irrevocable. You may stop distributing the work or offer it under other terms for future recipients, but existing users keep permission. On breach, rights under a 4.0 license terminate automatically. They are automatically reinstated from the date the violation is cured if it is cured within 30 days after the violator discovers it; the licensor may also expressly reinstate them. Cure does not erase possible liability for the period of violation. Older versions have different termination language and do not contain the same automatic 30-day mechanism. Dual licensing is permitted: you can offer the same work under a CC license and under a separate paid license, as long as the paid license does not conflict with the public CC offer.

The table orders the licenses from most permissive to most restrictive. Read it column by column, left to right. The first column that blocks your intended use tells you which license you cannot use. If you need both commercial use and sharing adaptations, you are looking at CC BY or CC BY-SA. If you need commercial use but want to block adaptations from being shared, CC BY-ND fits. If you want to allow adaptations but only for noncommercial purposes, the three NC licenses are your set. The column that matters most is the one that matches your non-negotiable condition.

What The Table Does Not Show

The table does not show the official compatibility rules for ShareAlike. CC BY-SA 4.0 is one-way compatible with GPLv3 for adapted material only. You can incorporate GPLv3 code into a BY-SA project, but a GPLv3 project cannot automatically incorporate BY-SA material. The table also does not show that the NonCommercial condition has no bright-line definition. Version 4.0 defines it as not primarily intended for or directed toward commercial advantage or monetary compensation. If your use has material commercial risk, do not rely on the table alone; get separate permission or qualified legal advice.

The table is built from the official license terms published by Creative Commons. The permissions shown are those granted by the legal code. For the exact legal language, open the deed for the license you are considering and click through to the legal code.