The Preprint Citation Index is a specialised index for searching preprints. As of summer 2023, it contains around two million preprints from five of the major repositories - arXiv, bioRxiv, medRxiv, chemRxiv, and Preprints.org.
To access it, select "Preprint Citation Index" from the drop-down menu on the main search screen:
You can then search using the normal Web of Science methods - the default search is topic, covering title, abstract, & keywords, and we recommend this is the most effective method for most searches.
The standard Web of Science sorting and filters are available for your results, but metadata is more limited than for published papers - the information on author affiliations or countries is not as comprehensive.
Individual records have a link to the source preprint (these will almost always be available as full-text open access) plus links to its citations, both by other preprints and by papers in the Web of Science Core Collection. Cited references are indexed for some preprints but not others. The metadata provided includes a link to multiple versions of the preprint if these exist.
It is important to note that preprints are not reliably connected to the "final" published version of a paper - if you have looked up a preprint, it may not be possible to find out if it was later published. Web of Science indexes preprints alongside other papers in a researcher's profile, so you can look through the combined publication list if needed to confirm this.