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

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


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


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

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

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


The license 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 license as long as the user complies with the following license terms:

  • provides adequate copyright and rights information (attribution)
  • attaches a link to the license
  • 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 license. CC licensing 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) license. The CC0 license 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.