What’s Included in a Journal Citation Reports (JCR) Report?

Short answer: A Journal Citation Reports (JCR) release is Clarivate’s annual, multi-metric report on journal performance. It reports far more than the Journal Impact Factor — also covering the Journal Citation Indicator (JCI), Eigenfactor Score, Article Influence Score, Immediacy Index, and Q1–Q4 quartile rankings for each journal, category by category. This page explains what’s actually inside a JCR release and how each of those figures works.

Looking for Clarivate’s official JCR platform to pull a specific journal’s current figures? That’s a subscription product at jcr.clarivate.com, accessed through an institutional Web of Science subscription — CASRAI does not mirror or host that data. What follows is CASRAI’s independent explanation of what a JCR release contains and how to read it.

What a Journal Citation Reports release actually contains

Journal Citation Reports (JCR) is not a single number — it is an annual, multi-metric report covering tens of thousands of journals. Each year’s release (e.g. “JCR 2026,” published June 2026 using 2025 citation data) gives every eligible journal its own JCR Profile page carrying several distinct, independently calculated indicators, not just the Journal Impact Factor:

• Journal Impact Factor (JIF) — citations in year Y to a journal’s citable items from years Y-1 and Y-2, divided by the count of those citable items. The metric most people mean when they say “impact factor.”
• JIF 5-Year — the same calculation extended to a five-year citation window, which smooths out year-to-year volatility for journals with slower citation uptake.
• Journal Citation Indicator (JCI) — introduced in the 2021 release. A field-normalized score (category average = 1.0) built so that journals in different subject categories — a chemistry journal and a history journal, for instance — can be compared on a common, discipline-adjusted scale in a way raw JIF cannot support.
• Eigenfactor Score and Article Influence Score — an eigenvector-style (“PageRank”-like) weighting of five years of citations that accounts for the prestige of the citing journal, not just the raw citation count, licensed by Clarivate from the University of Washington’s Eigenfactor project.
• Immediacy Index — how quickly a journal’s articles get cited in their year of publication, a proxy for how fast-moving a field or journal is.
• Quartile ranking (Q1–Q4) — a journal’s rank position within its assigned JCR subject category, expressed as a quartile of that category’s full ranked list.
• Cited Half-Life and Citing Half-Life — Cited Half-Life is the median age of a journal’s own articles that were cited in the current JCR year (a high cited half-life means the journal’s back catalogue keeps getting cited for a long time; a low one means its influence is concentrated in recent issues). Citing Half-Life is the mirror statistic: the median age of the items the journal itself cited that year, a rough proxy for how much a field or journal relies on older versus current literature.
• Supporting descriptive data — total citations, percentage of open-access articles, and category rank tables.

Confusing any one of these for “the JCR number” is a common source of miscommunication — a journal’s JIF, JCI, and quartile position can each tell a different story about the same journal in the same release year.

How quartile rankings are actually calculated

A journal’s Q1–Q4 quartile is determined by sorting every journal in its assigned JCR subject category by a ranking metric, then dividing that ranked list into four equal segments. Landing in Q1 means the journal outranks at least 75% of journals in its category for that metric and that release year. Two details matter in practice: a journal can be classified into more than one JCR category (common in interdisciplinary fields) and will carry a separate quartile per category, and — following a 2024 methodology change — arts and humanities categories are ranked by JCI rather than JIF, since Clarivate determined JCI’s field-normalization better suits how citation practices work in those disciplines. See CASRAI’s companion guide, Journal Impact Factor and Quartile Rankings, for a full worked walkthrough of finding and interpreting a specific journal’s quartile.

Secondary subject categories: why the same journal can be Q1 in one field and Q3 in another

Clarivate assigns each journal to one or more JCR subject categories based on the journal’s overall citation profile and subject scope, not on how the journal describes itself. Many journals — especially interdisciplinary ones — carry a primary category plus one or more secondary subject categories, and JCR calculates a completely separate quartile rank within each category the journal belongs to. A journal covering environmental chemistry at scale, a description that fits titles such as Environmental Science and Pollution Research, might rank Q1 within a narrower “Environmental Sciences” category, where its citation volume is strong relative to a smaller field, while ranking Q3 within a broader, more heavily cited “Chemistry, Multidisciplinary” category — both figures are correct simultaneously, and neither one is “the” quartile for that journal without specifying which category it refers to. This is also why comparing two journals’ quartiles is only meaningful when both figures come from the same JCR subject category: a Q1 ranking in a smaller, less-cited field is not evidence of a stronger journal than a Q2 ranking in a larger, more competitive one.

Which journals are eligible

JCR metrics are built from citation data captured across Clarivate’s Web of Science Core Collection indices — chiefly the Science Citation Index Expanded (SCIE), the Social Sciences Citation Index (SSCI), the Arts & Humanities Citation Index (AHCI), and the Emerging Sources Citation Index (ESCI). This eligibility list is more current than it might appear from older guidance: through 2022, only SCIE- and SSCI-indexed journals received a Journal Impact Factor. Starting with the 2023 JCR release, Clarivate extended JIF eligibility to all Web of Science Core Collection journals meeting its quality criteria, including AHCI and ESCI titles — over 9,000 journals received a JIF for the first time that year. A journal’s presence in Web of Science does not automatically mean a JCR profile exists for it: coverage still depends on which Core Collection index accepted it, and JCR builds its report only from that citation data, not from Web of Science search results directly.

Who publishes it, and history

JCR was created by Eugene Garfield and Irving H. Sher at the Institute for Scientific Information (ISI), with the first edition published in 1975 using 1974 citation data — the origin of the Journal Impact Factor itself. Ownership of ISI, and with it JCR, passed through the Thomson Corporation (1992), Thomson Reuters (formed 2008), and finally Clarivate (spun out and rebranded in 2016), which is the current publisher. The report moved from print to electronic distribution over the following decades and is now published as an online platform (jcr.clarivate.com), with JCI added in 2021 and the JIF-eligibility expansion to AHCI/ESCI journals landing in 2023, as described above. The 2026 release (published June 2026) covers 22,643 journals across 254 subject categories from 113 countries.

When JCR is released each year

Clarivate publishes a new JCR edition annually, historically in June, and names each release for the year it is published rather than the year of the citation data it contains — “JCR 2026” is the report published in June 2026, built from citations recorded during 2025 to articles published in the two (or five, for the 5-Year JIF) years before that. Every annual release also adds journals that newly qualified for a JCR profile that year and can assign some of them a Journal Impact Factor for the first time; CASRAI’s news coverage of the 2026 JCR’s first-time-JIF cohort covers one recent instance of that pattern. Journals in newer or fast-moving fields are where this is most visible: the AI and Ethics impact factor and the Communications Biology impact factor both belong to titles that were publishing and accumulating citations for several years before any JCR figure existed for them, which is why a search that returns no impact factor for a young journal is often reporting the indexing timeline rather than the journal’s citation performance. Because the release is annual rather than continuously updated, a journal’s JIF, JCI, and quartile figures are fixed for a full year between releases — checking “this year’s” number generally means checking whichever JCR edition is currently current, not a live-updating figure.

How JCR is accessed

JCR is a Clarivate subscription product — there is no free, complete way to browse the full official dataset. Most research university libraries carry access, commonly bundled with a Web of Science subscription, since the two products share the same underlying citation data. A library’s database list or a subject librarian is the fastest way to confirm access; a journal’s own website often states its current JIF or quartile directly, though that self-reported figure should still be treated as a claim to verify against the actual JCR profile page where citation-integrity questions matter (a scenario CASRAI’s guide on looking up a journal’s current Impact Factor covers in more depth). Confirming whether a journal is indexed at all — a prerequisite for it having any JCR metrics — is free via the Web of Science Master Journal List.

In practice, looking up a specific journal’s current quartile or rank means three checks, in order: first, confirm the journal is indexed in a Web of Science Core Collection index at all — free to check via the Web of Science Master Journal List guide, and worth doing before assuming a JIF or quartile exists, since journals are periodically removed from coverage and lose their JCR profile when that happens. Second, if indexed, confirm which JCR subject category (or categories) that indexing places it in, since the quartile is category-specific, as above. Third, pull the actual JCR Profile page for the current release through an institutional subscription rather than relying solely on a figure quoted on the journal’s own website or a third-party aggregator, particularly where the number is being used for a decision (a hiring file, a funding report) rather than general orientation.

JCR is not the same product as these adjacent things

• Web of Science — the citation-indexing and discovery platform JCR draws its data from. Searching or browsing Web of Science is not the same as accessing a JCR report, even where both are bundled in the same library subscription.
• SCIE / SSCI / AHCI / ESCI — the individual citation indexes within Web of Science’s Core Collection. A journal’s index membership determines its JCR eligibility, but the index itself is not JCR.
• The Journal Impact Factor — one metric reported inside JCR, not the report itself. “JCR” and “impact factor” get used interchangeably in casual conversation, but a JCR release also reports JCI, Eigenfactor, Article Influence, and quartile data that JIF alone does not capture.
• Scopus and its metrics (CiteScore, SCImago Journal Rank) — a wholly separate Elsevier product built on a different underlying citation database, with its own selection criteria and formulas. A journal’s Scopus-derived metrics and its Clarivate/JCR metrics will generally differ and are not interchangeable, even when both get informally called “the impact factor.” See CASRAI’s Scopus vs Web of Science vs OpenAlex comparison for the underlying database differences.

Known limitations and criticisms

JCR’s metrics were built to describe journals in aggregate, and most of the documented criticism of JCR concerns what happens when that aggregate, journal-level figure gets applied to something it was not designed to measure — a single article or a single researcher. A journal’s JIF is an average across all its citable items in a two-year window; citation counts within any journal are typically highly skewed, so a small number of heavily cited papers can carry a journal’s average well above the citation performance of most of its individual articles. Reported concerns with JCR-derived metrics specifically include: their use as a proxy in hiring, promotion, and funding decisions for work that individual figure was never calculated to represent; incentives toward editorial practices that inflate citation counts rather than research quality, including the citation manipulation covered in CASRAI’s guide on citation stacking and cross-journal citation inflation; and the difficulty of comparing figures across disciplines with very different baseline citation behaviour, which JCI (see above) was specifically introduced to address, though it has not eliminated cross-field comparison problems entirely.

The broader research-assessment reform movement takes direct aim at this gap between what JCR measures and how it gets used. The San Francisco Declaration on Research Assessment (DORA) and the Coalition for Advancing Research Assessment (CoARA) both call on institutions to stop using journal-level metrics like the JIF as a stand-in for the quality of an individual researcher’s work or an individual article. See CASRAI’s responsible metrics entry and the DORA and CoARA comparison guide for the fuller reform-movement context. This page describes what JCR is and contains; see CASRAI’s Journal Impact Factor and Quartile Rankings guide for a more extended treatment of how to use — and not misuse — the metrics it reports.

Frequently Asked Questions

Is JCR the same thing as the Journal Impact Factor?

No. The Journal Impact Factor is one metric reported inside a JCR release, not the report itself. A single JCR release also reports the Journal Citation Indicator, Eigenfactor Score, Article Influence Score, Immediacy Index, Cited and Citing Half-Life, and quartile rankings alongside JIF, so “JCR” and “impact factor” are not interchangeable even though they get used that way in casual conversation.

How is a journal’s JCR quartile ranking calculated?

A journal’s Q1–Q4 quartile comes from sorting every journal in its assigned JCR subject category by a ranking metric — JIF for most categories, or JCI for arts and humanities categories following a 2024 methodology change — and dividing that ranked list into four equal segments. Landing in Q1 means the journal outranks at least 75% of the journals in its category for that metric and release year. See CASRAI’s Journal Impact Factor and Quartile Rankings guide for a full worked example.

Can the same journal have different quartile rankings in different JCR categories?

Yes. Clarivate assigns many journals — especially interdisciplinary ones — to more than one JCR subject category, and calculates a completely separate quartile within each category the journal belongs to. A journal can rank Q1 in a narrower category and Q3 in a broader, more heavily cited one at the same time, and both figures are correct simultaneously.

How do I find out if a journal is indexed in JCR?

Check first whether the journal is indexed in one of the Web of Science Core Collection indices — SCIE, SSCI, AHCI, or ESCI — since a JCR profile only exists for journals accepted into one of those indices. This is free to confirm via the Web of Science Master Journal List; being present in Web of Science does not automatically mean a JCR profile exists for that journal.

What is the Journal Citation Indicator (JCI), and how does it differ from JIF?

JCI is a field-normalized score, introduced in the 2021 JCR release, built so that the average score across a category equals 1.0, which lets journals in different subject categories be compared on a common, discipline-adjusted scale. JIF, by contrast, is a raw citations-per-citable-item ratio with no adjustment for how citation behaviour varies between fields — a gap that is also why arts and humanities categories are now ranked by JCI rather than JIF.

How can I access a journal’s JCR report?

JCR is a Clarivate subscription product, and there is no free way to browse the complete official dataset. Most research university libraries provide access, commonly bundled with a Web of Science subscription. A journal’s own website often states its current JIF or quartile, but that self-reported figure is worth verifying against the actual JCR Profile page when the number is being used for a decision such as a hiring file or funding report.