Free licences

In compliance with intellectual property rights, and unless third-party rights, legal requirements, Rectorate decisions, other reasonable interestsor property laws prohibit it, research data should be assigned an open uselicense.

Funding bodies also support this demand. Please note that only free licences meet the criteria for open data. You can find more information on this topic on our subpage about licences, opens in new window.

By granting a free licence, you as the owner allow others to use your research data. Free licences allow users to copy, distribute, use and edit data, even for commercial purposes. Free licences apply worldwide and cannot be converted into more restrictive licences later.


A suitable free licence for source code would be the GNU General Public Licence (GPL, opens an external URL in a new window), for example.

For metadata, you can use the Creative Commons Public Domain Licence (CC0, opens an external URL in a new window).

For all other types of research data, we recommend the Creative Commons licence with author's attribution (CC BY, opens an external URL in a new window).


The licence CC BY 4.0, opens an external URL in a new window allows users to do the following with the data:

  • share – i.e. replicate and redistribute the material in any format or medium
  • edit – i.e. remix the material and build on it for any purpose, even commercially


The licensor cannot revoke a licence as long as the user complies with the following licence terms:

  • provides adequate copyright and rights information (attribution)
  • attaches a link to the licence
  • makes known whether changes have been made

This information may be provided in any appropriate manner, but not in such a way as to give the impression that the licensor especially supports a user or use in particular.


To be clear, authorship is never lost when awarding a CC licence. CC licencing in no way takes away your rights as an author, but simply awards certain rights to others.


Using CC0, opens an external URL in a new window instead of CC BY for metadata has the advantage that search engines will find such public domain content more easily, which facilitates the dissemination and maximum discoverability of your data.

In many areas it has become common to make data and metadata freely available to the public under a Creative Commons CC0 1.0 Universal (CC0) licence. The CC0 licence promotes a public domain dedication, in other words, metadata may be used without restriction and without further permission.

CC0 is a tool which frees metadata worldwide from copyright restrictions. Even attribution is no longer necessary in this case. In some legal systems, metadata per se is free from copyrights.


Our icon for "legal aspects": balanced beam balance in a circle.

These explanations are to be understood as support and initial orientation about free licenses and not legal advice. In case of doubt, please always contact the legal departments of our university.

Good to know:

There are tools available to help you choose a suitable license, for example the public-license-selector, opens an external URL in a new window.

Especially for software:, opens an external URL in a new window