Scopus and Web of Science are the two best-known citation databases in the world. Universities, funders and selection committees use them to judge where a paper has been published and how often it is cited. They overlap a great deal, but they are not the same, and the difference matters when a requirement names one of them.
Who runs them
- Scopus is run by Elsevier
- Web of Science is run by Clarivate
Both select the journals they index. Publishers apply, and the journals are judged against published criteria such as peer review, editorial standards, regular publication and international relevance. Both also re-evaluate journals and can stop covering them.
Coverage
Scopus covers a larger number of journals across science, technology, medicine, the social sciences and the arts and humanities, along with book series, books and conference proceedings.
Web of Science is more selective. The part most requirements refer to is its Core Collection, which includes several indexes:
- SCIE: Science Citation Index Expanded
- SSCI: Social Sciences Citation Index
- AHCI: Arts and Humanities Citation Index
- ESCI: Emerging Sources Citation Index
Many journals are in both databases. Many others are in only one. A journal being in Scopus tells you nothing about Web of Science, and the reverse is also true.
Metrics
Each database comes with its own journal metrics:
- Web of Science: the Journal Impact Factor (JIF), published each year in Clarivate's Journal Citation Reports (JCR). Since the 2023 release, journals in all Core Collection indexes, including ESCI and AHCI, receive an Impact Factor.
- Scopus: CiteScore, published by Elsevier, along with SJR (SCImago Journal Rank) and SNIP (Source Normalized Impact per Paper).
Both systems also rank journals within each subject, most commonly as quartiles from Q1 (the top 25%) to Q4. Here is a detail that surprises many researchers: the same journal can sit in different quartiles depending on whether you use JCR, SJR or CiteScore, and depending on the subject category. If your requirement names a quartile, find out which source it means.
At a glance
| Scopus | Web of Science | |
|---|---|---|
| Run by | Elsevier | Clarivate |
| Size | Broader | More selective |
| Main journal metric | CiteScore (plus SJR, SNIP) | Journal Impact Factor |
| Free way to check a journal | Scopus Sources | Master Journal List |
| Author identifier | Scopus Author ID | Web of Science ResearcherID |
Which do you need?
Read your requirement carefully, word by word:
- "Scopus indexed" means the journal must be covered in Scopus at the time of publication
- "Web of Science" or "SCI/SSCI" may mean any Core Collection index, or only some of them. Ask specifically whether ESCI counts
- "Impact factor journal" usually means a journal with a Clarivate JIF. Be wary of other "impact factors" sold by little-known websites; they are not the same thing
- "Q1 or Q2" needs a source: JCR, SJR or CiteScore
When the rule is unclear, ask your department or research office for it in writing. It is far easier than arguing about it after publication.
Your citations will differ too
Because the databases cover different journals, your citation counts and h-index will usually be different in each, and different again in Google Scholar. None of them is "wrong". When you report your metrics, say which database they come from, and keep your Scopus Author ID and ResearcherID profiles tidy so your papers are credited to you.
How to check a journal
Use Scopus Sources for Scopus, and the Web of Science Master Journal List for Web of Science. Both are free. Search by ISSN, and confirm that the journal is currently covered. Our step-by-step guide to checking Scopus indexing walks you through it.
Not sure which database or journal suits your paper? Our journal selection service gives you a shortlist with proof of indexing for each journal. You can also read more about Scopus and Web of Science.
