CWTS takes next step in open research information transition
Institutional development image: Bonnie Kitahata on Unsplash
As a next step in its open research information transition, CWTS will discontinue its use of data from the Clarivate Web of Science database. This is announced in a joint statement issued today by CWTS and Clarivate.
At CWTS we have a long history, going back to the 1980s, in performing scientometric analyses using Web of Science data. This includes the use of Web of Science data in the CWTS Leiden Ranking and in research analytics services we provide to organisations across the research system. CWTS has an agreement with Clarivate through which we have bulk access to the raw data in the Web of Science database.
Open research information
One of our strategic priorities at CWTS is to make a transition from proprietary to open research information. We are working on this in our Information & Openness focal area. We are also one of the initiators of the Barcelona Declaration on Open Research Information, an initiative launched in 2024 that promotes openness of research information.
Our commitment to open research information led to the launch of the Open Edition of the Leiden Ranking in 2024. Unlike the Traditional Edition of the Leiden Ranking, which is based on proprietary Web of Science data, the Open Edition is fully based on open data from the OpenAlex database. More recently, we have also started to strengthen our collaboration with OpenAIRE.
Discontinuation of use of Web of Science data
Today we announce a next step in our transition to open research information: CWTS will discontinue the use of Web of Science data, both in the Leiden Ranking and in the services we offer to external organisations.
On November 4, 2026, the final update of the Leiden Ranking Traditional Edition based on Web of Science data will be released. From 2027 onward, the Traditional Edition of the Leiden Ranking will be discontinued. Only the Open Edition will remain.
More information can be found in this joint statement by CWTS and Clarivate.
Leiden University
Leiden University has a subscription to the Web of Science database. We note that the decision made by CWTS to discontinue its use of Web of Science data does not affect the university’s Web of Science subscription.