SCI vs SCIE: Why There Is No Longer a Difference, and What ESCI vs SCIE Means Instead

Reviewed by the NeucitePress Editorial Board — PhD academics, peer-reviewed journal editors and medical communication specialists.

Last updated and fact-checked: October 2026 • Every figure below is taken from the named primary source on the date shown • Reading time: 6 minutes

Where SCI came from and why the name persists

The Science Citation Index was created by Eugene Garfield’s Institute for Scientific Information and, in Clarivate’s words, Web of Science “started with the Science Citation Index which was released in 1964”. For decades it was a selective print and CD-ROM product, and the Science Citation Index Expanded was the larger online version. That history is why older guides describe SCI as an “elite subset” of SCIE.

The name outlived the product because research-evaluation systems adopted it. Promotion rules, PhD regulations and national journal lists in many countries still say “SCI-indexed”. When they do, they are describing the Web of Science Core Collection, or SCIE specifically, using a label that Clarivate itself no longer uses.

What Clarivate offers today

Clarivate’s “Database descriptions and quick links” (updated 24 June 2026) and “Web of Science coverage details” (updated 18 August 2026) list the Core Collection as:

The Core Collection holds more than 22,000 journals and 2.64 billion cited references (Clarivate, August 2026). The Master Journal List, Clarivate’s public lookup, offers filters for SCIE, SSCI, AHCI and ESCI; there is no SCI filter.

ESCI vs SCIE: the distinction that matters

Clarivate evaluates every journal against 28 criteria: 24 quality criteria and 4 impact criteria. The rules, from Clarivate’s selection-criteria page (accessed 13 Oct 2026):

• “All new submissions are evaluated using the 24 quality criteria only, and if selected for coverage are added to ESCI.”
• “ESCI journals that gain impact move to SCIE, SSCI or AHCI.” Clarivate triggers that review itself, “when citation activity suggests the criteria may be met”; publishers cannot request it.
• “SCIE, SSCI and AHCI journals that decrease in impact move to ESCI.”
• Flagship journals “must continue to pass all 24 quality criteria as well as meet all 4 impact criteria”.

The four impact criteria are comparative citation analysis, author citation analysis, editorial board citation analysis and content significance. The last can be met by content that is unique to a region or specialty, so SCIE is not reserved for high-citation fields. Fewer than 15% of evaluated journals pass the 24 quality criteria at all (Clarivate, March 2023).

The metric difference that used to separate the tiers is gone. Clarivate announced on 26 July 2022 that from JCR 2023 every Core Collection journal, including ESCI, would receive a Journal Impact Factor; JCR 2023 gave 9,136 journals their first JIF, and JCR 2024 placed ESCI journals in the same category rankings as SCIE and SSCI journals. Our guide to the 28 Web of Science criteria lists each criterion by stage, and the ESCI guide covers the move from ESCI to SCIE.

How to check a journal’s index

1. Open the Master Journal List and search by title or ISSN.
2. Read the “Web of Science Core Collection” line on the record: it names SCIE, SSCI, AHCI or ESCI.
3. If the journal is not in the list, it is not in the Core Collection, whatever its website says.
4. For the Impact Factor and category rank, use the Journal Citation Reports entry; the Master Journal List shows the JCI and category only.

What to tell authors and administrators

When a rule says “SCI-indexed”, ask what the rule’s author meant, because three readings are common and they differ:

For an editor, the practical goal is unchanged by the label: pass the 24 quality criteria to enter ESCI, then build the citation record and distinctive content that Clarivate’s impact review looks for. A journal that advertises itself as “SCI-indexed” while sitting in ESCI should correct the wording; Clarivate’s “validity of statements” criterion applies to what a journal says about itself.

Frequently asked questions

Is SCI still a Clarivate index?

No. Clarivate’s current database descriptions (updated 24 June 2026) and coverage details (updated 18 August 2026) list SCIE, SSCI, AHCI, ESCI, the Book Citation Index, the Conference Proceedings Citation Index and Index Chemicus. There is no separate Science Citation Index, and the Master Journal List has no SCI filter.

So what does “SCI journal” mean when a university or funder uses the term?

In practice it means a journal in the Science Citation Index Expanded, or more loosely any journal in the Web of Science Core Collection. The term survives in national evaluation schemes and promotion rules, especially in China, Korea and India, as shorthand rather than as a Clarivate category. Check the exact wording of your institution’s rule: some accept ESCI, some do not.

Can a journal be in both SCI and SCIE?

The question no longer applies. SCIE is the only science index Clarivate offers, so every science journal in the Core Collection is an SCIE or an ESCI journal.

What is the real distinction today?

ESCI versus SCIE (or SSCI and AHCI for the social sciences and humanities). All new journals enter ESCI after passing 24 quality criteria. A journal moves to SCIE only when Clarivate’s internal review finds it meets 4 additional impact criteria. Journals can also move back from SCIE to ESCI if impact falls.

Do ESCI journals have an Impact Factor?

Yes, since JCR 2023. ESCI journals have been ranked in the same subject categories as SCIE journals since JCR 2024.

How do I check whether a journal is in SCIE or ESCI?

Search the Clarivate Master Journal List (mjl.clarivate.com). The record names the index. Do not rely on a journal’s own website or a third-party list.

Sources (primary, with access date)

• Clarivate. Database descriptions and quick links, updated 24 June 2026 (SCIE 182 categories; SSCI 47; no SCI).
• Clarivate. Web of Science coverage details, updated 18 August 2026.
• Clarivate. Web of Science Core Collection (SCI released 1964; 22,000+ journals). Accessed 13 October 2026.
• Clarivate. Journal evaluation process and selection criteria (ESCI pathway, 24 + 4 criteria). Accessed 13 October 2026.
• Clarivate. Changes to the 2023 Journal Citation Reports, 26 July 2022; JCR 2023 release, 28 June 2023; JCR 2026 release, 17 June 2026.
• Clarivate. Supporting integrity of the scholarly record, 20 March 2023 (fewer than 15% pass).
• Clarivate. Master Journal List. Accessed 13 October 2026.