Examples
Worked examples
- Is an instance
A researcher checking PLOS's own journal-information page before citing a PLOS ONE Impact Factor, finding that PLOS explicitly states it does not consider the metric reliable and promotes CiteScore, SJR, and article-level metrics instead.
- Is an instance
A research office needing a specific current JIF number for a tenure file looking it up directly in jcr.clarivate.com via institutional library access, or requesting it from PLOS as PLOS's own policy invites, rather than quoting a third-party tracker.
Counter-examples
Looks similar, but isn't
- Not an instance
Citing a third-party JCR-tracking aggregator's or Wikipedia's number for PLOS ONE's Impact Factor as though PLOS itself published or endorsed it -- PLOS's own policy explicitly declines to promote the metric.
- Not an instance
Citing PLOS ONE's CiteScore (a separate Elsevier/Scopus metric, four-year window) as if it were the journal's Clarivate JIF -- they are different metrics from different organizations with different windows and denominators.
- Not an instance
Assuming an individual highly cited PLOS ONE article 'has' the journal's JIF -- the metric, where it exists, is computed at the journal level across tens of thousands of articles a year, not the article level.
Editorial commentary
PLOS ONE’s Journal Impact Factor for the 2025 JCR data year is widely reported as 2.8 — but no primary source states it publicly, and that is the whole difficulty. A JIF is computed for PLOS ONE: PLOS’s own indexing list names Web of Science among the services covering the journal, which is what makes it JCR-eligible, so Clarivate calculates a figure for it each June. PLOS, however, declines on principle to publish that figure, and Clarivate’s Journal Citation Reports sits behind an institutional subscription. The 2.8 in circulation therefore reaches you through secondary sources only. This page sets out exactly who reports it, what CASRAI could and could not confirm on 23 August 2026, and whether the number is safe to cite.
PLOS ONE’s Impact Factor in 2026: is the 2.8 you have seen real?
Short answer: 2.8 for the 2025 JCR data year is the figure consistently reported by secondary sources, and CASRAI found nothing contradicting it — but it is confirmed by neither PLOS nor Clarivate in public. Cite it only with both the data year and the source named, or obtain it from JCR directly. Here is precisely who says what.
- PLOS (the publisher) — states no number, by policy. Its PLOS ONE Journal Information page says verbatim: “We do not consider Impact Factor to be a reliable or useful metric to assess the performance of individual articles but will provide the metric to individuals when specifically requested.” No numeric Impact Factor appears anywhere on that page. Read directly at journals.plos.org/plosone/s/journal-information, 23 August 2026.
- Clarivate (the source of record) — computes it, but paywalled. The JCR is the only authoritative place the figure is published, and it requires an institutional Web of Science subscription, so CASRAI could not consult it. Clarivate’s own public citation-reports endpoint does confirm the vintage: the newest citation report it lists is the 2025 data year, retrieved 23 August 2026. A 2025-data-year figure for PLOS ONE therefore certainly exists.
- Clarivate’s Master Journal List — could not be checked. CASRAI tried to confirm PLOS ONE’s Web of Science index membership at mjl.clarivate.com on 23 August 2026 and could not: the site returned a maintenance page (“MJL will be back online soon”) and its search backend rejected every query. CASRAI therefore cannot say which Web of Science index (SCIE or ESCI) carries PLOS ONE, only that the publisher lists Web of Science coverage.
- Wikipedia — 2.8, attributed to 2025. The English Wikipedia article’s infobox carries
impact = 2.8andimpact-year = 2025, and its body reads “According to the Journal Citation Reports, the journal has a 2025 impact factor of 2.8.” That is the revision of 31 July 2026. Wikipedia is a secondary source and offers no citation trail back to a JCR record CASRAI could open. - Third-party JCR trackers — also 2.8. bioxbio’s PLOS ONE table gives 2.8 for “2025 (2026 update)”, following 2.6 for 2024, 2.9 for 2023 and 3.7 for 2022 (retrieved 23 August 2026). Other aggregators report 2.8 with a Q2 quartile placement. These sites do not disclose their retrieval method, so CASRAI treats agreement among them as weak corroboration rather than confirmation.
What that adds up to. The number is not in dispute — every secondary source CASRAI checked reports 2.8 for the same data year. What is missing is not agreement but provenance: there is no publicly readable primary record. That distinction governs how you should use it. For an informal comparison, 2.8 (2025) is a reasonable working figure. For a CV, tenure file, grant application or funder report, quote it as “2.8 (2025 JCR data year)” with your source named — or better, pull it from JCR through your library so you can attribute it to Clarivate directly. Either route is defensible; presenting an aggregator’s number as though Clarivate or PLOS had confirmed it is not.
How to verify it yourself. If your institution subscribes to Web of Science, sign in at jcr.clarivate.com, search for PLOS ONE, and read the Journal Impact Factor for the 2025 data year off the journal profile; that is the authoritative record. If you have no institutional access, PLOS’s own policy wording commits it to supplying the metric on request, so email the journal and ask. CASRAI’s guide to looking up a journal’s Impact Factor walks through the lookup.
What CASRAI could verify at source
- ISSN: 1932-6203 — Crossref journal record, checked 23 August 2026.
- Publisher: Public Library of Science (PLOS) — Crossref journal record, checked 23 August 2026.
- PubMed / MEDLINE: Currently indexed for MEDLINE; MEDLINE coverage v1n1, 2006- — NLM Catalog record, checked 23 August 2026.
- DOAJ: Listed in DOAJ; record added 30 March 2007 — DOAJ API, checked 23 August 2026.
- Indexing the publisher itself lists: Crossref, Dimensions, DOAJ, Google Scholar, PubMed, PubMed Central, Scopus, Web of Science, AGRICOLA, Biological Abstracts, BIOSYS Previews, CABI CAB Abstracts, CABI Global Health, CAPES, CAS, CNKI, EconBiz, Embase, Food Science and Technology Abstracts, Journal Guide, MEDLINE, Psychinfo, RePEc and Zoological Record — the publisher’s own journal page, 23 August 2026.
- Journal Impact Factor: not confirmable at a primary source. Reported as 2.8 for the 2025 JCR data year by Wikipedia’s infobox (revision of 31 July 2026) and by bioxbio’s tracker table; PLOS publishes no figure and Clarivate’s JCR is paywalled. Clarivate’s Master Journal List was unreachable when checked, 23 August 2026.
PLOS’s own policy: it does not promote an Impact Factor
PLOS’s journal-information page states directly: “We do not consider Impact Factor to be a reliable or useful metric to assess the performance of individual articles but will provide the metric to individuals when specifically requested.” CASRAI verified this language directly on journals.plos.org’s PLOS ONE journal-information page (last verified 23 August 2026); the same boilerplate policy language appears across PLOS’s journal-information pages. Rather than headlining a JIF, PLOS’s own metrics pages promote article-level metrics (ALMs), Scopus’s CiteScore and SJR, and the author-level h-index. This position is consistent with the stance of DORA (the San Francisco Declaration on Research Assessment) and the CoARA coalition, both of which discourage using a single journal-level citation ratio as a stand-in for the quality of an individual article or researcher — PLOS is a DORA signatory and its metrics-page language reflects that commitment in practice, not just in principle.
What that means for citing a number
Because PLOS itself declines to headline a JIF, any specific figure in circulation for PLOS ONE is necessarily coming from a third party — most commonly Clarivate’s own Journal Citation Reports (JCR), which does compute and publish a JIF for PLOS ONE as a JCR-indexed title even though PLOS does not foreground that number on its own site. Clarivate’s JCR database itself sits behind institutional-subscription authentication and could not be checked directly by CASRAI. If a specific figure is genuinely needed — for a CV, grant narrative, or tenure file — the reliable path is: (1) check whether your institution has JCR access via a library subscription and look up PLOS ONE directly in jcr.clarivate.com, current cycle the 2025 data year, released June 2026; or (2) per PLOS’s own stated policy above, request the figure directly from PLOS. Do not present a number quoted by a third-party JCR-tracking aggregator or Wikipedia’s infobox as though Clarivate or PLOS had confirmed it — aggregators update on their own schedules and can diverge from Clarivate’s actual current release. Reporting such a figure is perfectly defensible when you name the source and the data year, as this page does above; laundering it into an unattributed “PLOS ONE’s impact factor is X” is not.
PLOS ONE’s Impact Factor over time: the 5-year trend
The 2.8 figure widely reported for the 2025 JCR data year did not appear from nowhere — third-party JCR trackers show PLOS ONE’s reported Impact Factor moving within a fairly narrow band over the preceding several years. The table below collects the same year-by-year figures already cited above from bioxbio’s tracker table (retrieved 23 August 2026); CASRAI has not independently verified each individual year directly against Clarivate’s JCR, only the general corroboration of the current 2025 figure across sources, so treat the historical values with the same sourcing caveat as the current one.
| JCR data year | Reported Impact Factor | Year-over-year change |
|---|---|---|
| 2022 | 3.7 | — |
| 2023 | 2.9 | Down 0.8 |
| 2024 | 2.6 | Down 0.3 |
| 2025 | 2.8 | Up 0.2 |
Read this trend cautiously rather than as a definitive trajectory: the figures come from a third-party tracker, not from Clarivate or PLOS directly, for the reasons set out above. What the pattern does show is a decline from 2022’s 3.7 through 2024’s 2.6, with a small uptick to 2.8 for 2025 — consistent with normal year-to-year JIF movement for a high-volume megajournal rather than a sharp directional shift. Cite only the single data-year figure you actually need, with its source and year named, per the guidance above.
What quartile is PLOS ONE’s Impact Factor in?
Clarivate’s JCR ranks every indexed journal against the other journals in its subject category by Impact Factor, then divides that ranked list into four equal quartiles: Q1 is the top 25% of journals in the category, Q2 the next 25%, then Q3 and Q4. A journal’s quartile is category-specific and can differ across the several subject categories a multidisciplinary title like PLOS ONE is classified under, since the same Impact Factor ranks differently depending on which category’s journal list it is compared against.
Third-party trackers reporting PLOS ONE’s 2.8 (2025) Impact Factor place it in Q2 for at least one of its JCR subject categories — again, a figure CASRAI could not verify directly against Clarivate’s JCR, which requires institutional access. Because PLOS ONE is indexed across a wide range of JCR categories (it publishes across essentially every scientific and medical discipline), its quartile placement is not a single fixed value the way it might be for a narrowly scoped, single-category journal; pull a specific quartile-by-category breakdown from JCR directly, the same way the JIF itself should be for anything citation-sensitive like a CV or grant file.
What the JIF measures, mechanically, when it does exist
Where a journal does carry a Clarivate JIF, the figure is a ratio: citations received in a given JCR data year to citable items (articles and reviews) the journal published in the two preceding years, divided by the number of those citable items. PLOS ONE, published by the Public Library of Science (PLOS), has been JCR-indexed since shortly after its 2006 launch and now publishes on the order of thousands of articles annually across essentially every scientific and medical discipline, from biology and medicine to physical sciences, social sciences, and engineering.
Why PLOS ONE’s megajournal model matters here
PLOS ONE was one of the first journals to popularize the megajournal model: it peer-reviews submissions for scientific and methodological soundness — is the research rigorously conducted and reported, are the conclusions supported by the data — rather than for subjective judgments of novelty, significance, or likely impact. That editorial criterion is deliberately decoupled from citation-based metrics like the JIF, which is directly consistent with PLOS’s own stated reluctance to promote the metric: a journal that accepts on soundness rather than anticipated impact has less editorial reason to foreground a citation-based average. Because PLOS ONE accepts technically sound work across an unusually wide range of fields and topics rather than curating for anticipated impact within a narrow scope, its journal-wide average citation figure, where one exists, blends together very different citation norms from very different disciplines — a dynamic that also applies, to a lesser degree, to other broad multidisciplinary titles, but is especially pronounced for a megajournal operating at PLOS ONE’s scale.
Why this number alone is a poor stand-in for quality
Citation-tracking organizations including DORA, the CoARA coalition, and Clarivate itself caution against over-relying on a single journal-level metric to judge an individual article or researcher. For PLOS ONE specifically, this caution is reinforced by both the journal’s own editorial philosophy (soundness-based acceptance, decoupled from impact) and PLOS’s own explicit policy of not promoting the metric — using PLOS ONE’s JIF, sourced from wherever it can be found, to infer anything about a particular published article’s significance runs directly against how PLOS says it selects what to publish and how it wants the journal evaluated in the first place.
Counter-example
PLOS ONE’s CiteScore (a separate Elsevier/Scopus metric using a four-year citation window and a broader document set, and one of the metrics PLOS does actively promote) is not the same figure as its Clarivate JIF, and reporting one as if it were the other is a common sourcing error. Likewise, PLOS ONE’s soundness-only peer review is not itself evidence for or against the journal’s JIF being high or low — the two are separate systems (editorial acceptance criteria vs. a citation-count ratio) measuring different things, and neither validates the other.
Keeping this current
Last verified by CASRAI: 23 August 2026, directly against journals.plos.org/plosone/s/journal-information. This page reports the 2.8 (2025 JCR data year) figure that Wikipedia and third-party trackers carry, and names them as the source, because PLOS’s own stated policy is not to publish one and Clarivate’s JCR is paywalled; check jcr.clarivate.com (institutional access required) to attribute the number to Clarivate directly. JCR figures generally refresh each June with Clarivate’s new release, so any figure obtained from JCR directly should be rechecked after that date.
Related terms
- Journal Impact Factor (JIF) — the general metric this page discusses in the specific context of PLOS’s policy toward it.
- Nature Communications’ Journal Impact Factor (JIF) — a comparison point from a publisher that does headline its JIF.
- Scientific Reports’ Journal Impact Factor (JIF) — another journal-specific illustration of the same metric, also a megajournal.
- Nature’s Journal Impact Factor (JIF) — a selectively curated, non-megajournal comparison point.
- Science Advances’ Journal Impact Factor (JIF) — another journal-specific illustration of the same metric.
- Cell Reports’ Journal Impact Factor (JIF) — another journal-specific illustration of the same metric.
- CiteScore — the metric PLOS actively promotes in place of the JIF.
- DORA (San Francisco Declaration on Research Assessment) — the reform commitment behind PLOS’s stated position.
- Is PLOS ONE a predatory journal? — a related question about PLOS ONE’s editorial legitimacy and model.
Frequently Asked Questions
What is PLOS ONE’s current Journal Impact Factor?
Secondary sources consistently report 2.8 for the 2025 JCR data year: Wikipedia’s infobox (revision of 31 July 2026) and bioxbio’s tracker table both give that figure. No primary source states it publicly — PLOS declines to publish an Impact Factor as a matter of policy, and Clarivate’s JCR is behind an institutional subscription. CASRAI could not open a primary record for it on 23 August 2026, and Clarivate’s Master Journal List was unreachable that day. Treat 2.8 (2025) as a working figure, always cite it with the data year and the source named, and pull it from JCR through your library if it is going into a CV, tenure file or grant application.
Is PLOS ONE indexed in the Journal Citation Reports (JCR)?
Yes. PLOS ONE has been JCR-indexed since shortly after its 2006 launch and receives its own annual Impact Factor computation from Clarivate like every other JCR-indexed title, even though PLOS does not headline that figure on its own site.
Why doesn’t PLOS publish PLOS ONE’s Impact Factor directly?
PLOS’s stated policy, confirmed directly on its journal-information page, is that it does not consider Impact Factor a reliable or useful measure of an individual article’s performance, though it will provide the figure on request. PLOS instead promotes article-level metrics, CiteScore, SJR, and the h-index — a position consistent with DORA and CoARA guidance against over-relying on a single journal-level citation metric.
How is PLOS ONE’s Journal Impact Factor calculated, where one exists?
The JIF is a ratio: citations recorded in the JCR data year to the journal’s citable items (articles and reviews) from the two preceding years, divided by the number of those citable items. This is the same calculation Clarivate applies to every JCR-indexed journal; only the citation and publication volume feeding it differs between titles.
Is PLOS ONE’s Impact Factor the same as its CiteScore?
No. CiteScore is a separate metric published by Elsevier/Scopus that uses a four-year citation window and a broader document set, while the Journal Impact Factor is Clarivate’s two-year-window metric published in the JCR. PLOS actively promotes CiteScore over the JIF; reporting one figure as though it were the other is a common sourcing error regardless.
Does PLOS ONE’s Impact Factor say anything about the quality of a specific article?
Not reliably, and PLOS’s own stated position agrees: it does not consider the JIF a useful measure of an individual article’s performance. DORA and the CoARA coalition caution against using a journal-level metric like the JIF as a proxy for the quality of an individual paper or the merit of its authors, particularly for a megajournal like PLOS ONE whose soundness-only editorial criteria are explicitly decoupled from citation-based judgments of impact.
What is PLOS ONE’s Impact Factor trend over the last five years?
Third-party trackers report PLOS ONE’s Impact Factor at 3.7 (2022), 2.9 (2023), 2.6 (2024), and 2.8 (2025 JCR data year) — a decline followed by a small uptick, typical of normal year-to-year movement for a high-volume megajournal rather than a sharp trend in either direction. These are third-party figures; CASRAI could not verify each year directly against Clarivate’s JCR.
Is PLOS ONE a Q1 or Q2 journal?
Third-party trackers place PLOS ONE’s reported 2.8 (2025) Impact Factor in Q2 for at least one of its JCR subject categories. Because PLOS ONE is indexed across many categories as a multidisciplinary megajournal, its quartile placement can vary by category; check Clarivate’s JCR directly via institutional access for a category-specific answer.
For a comparable large open-access title, see Frontiers in Immunology (JIF).
Machine-readable encodings
Use in your systems
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