PLOS ONE Formatting Requirements: Complete Author Guide

PLOS ONE uses an unstructured abstract with a generous 300-word limit.

• Word limit: 300 words maximum
• Structure: Single paragraph, no subheadings
• Citations: Not allowed in the abstract
• Content: Should cover background, objective, methods, results, and conclusions

The 300-word cap gives you significantly more room than Nature (150), Cell Reports (150), or JCI (200). Use this space wisely. You can include more methodological detail and quantitative results than at most journals.

Despite being unstructured, your abstract should follow a logical flow: what the problem is, how you addressed it, what you found, and what it means. Some PLOS ONE reviewers specifically comment on abstracts that lack this implicit structure.

Keywords: PLOS ONE doesn't require author-submitted keywords in the traditional sense. Instead, authors select subject categories from a predefined taxonomy during submission. These categories are used for indexing and reviewer matching.

PLOS ONE places no strict limit on the number of figures or tables, which aligns with its no-word-limit philosophy. However, the journal has specific technical requirements for figure quality.

Figure specifications:

PLOS-specific figure rules:

• Figures must be uploaded as separate files, not embedded in the manuscript
• Each figure file must be named according to PLOS convention: Fig1.tif, Fig2.tif, etc.
• PLOS uses a two-column layout, so figures should be designed for either single-column (roughly 3.27 inches/83 mm) or full-width (roughly 6.83 inches/173 mm) display
• No text should be smaller than 8 pt in the final figure

Table requirements:

• Tables must be included in the manuscript file (Word or LaTeX), not as separate image files
• Every column must have a header
• Use the PLOS table style: horizontal rules at top, bottom, and below headers. No vertical rules.
• Large tables (more than 1-2 pages) should be submitted as Supporting Information in a spreadsheet format

Supporting Information figures and tables: Labeled as S1 Fig, S2 Fig, S1 Table, S2 Table, etc. These appear in the Supporting Information section. Unlike some journals, PLOS ONE doesn't compile these into a single PDF. Each is uploaded as a separate file.

PLOS ONE uses a numbered citation system based on Vancouver style, but with some PLOS-specific modifications.

In-text citations: Numbers in brackets, not superscripts. Example: "as demonstrated previously [1, 2]." Multiple citations are separated by commas within brackets. Ranges use an en dash: [3-7].

This is a critical detail. PLOS ONE uses brackets, not superscript numbers and not parentheses. Authors who've been formatting for Nature (superscript) or PNAS (parentheses) need to adjust.

Reference list format:

1. Smith AB, Jones CD, Williams EF. Title of article in sentence case. PLoS ONE. 2024;19(3):e0301234. doi:10.1371/journal.pone.0301234

Key formatting details:

• Author names: Last name, then initials without periods (e.g., "Smith AB")
• List all authors up to 6. For 7 or more, list the first 6 followed by "et al."
• Journal names abbreviated per NLM standards
• Include volume, issue number in parentheses, and page/article number
• DOIs are required for all references that have them
• URLs and access dates required for web references

Important: PLOS ONE requires DOIs in references. This is enforced more strictly than at most journals. If a cited work has a DOI, it must be included. Missing DOIs will be flagged during technical review.

There's no reference cap. Cite what's necessary.

The Data Availability Statement is one of PLOS ONE's defining features. The journal was a pioneer in requiring open data, and the policy is strictly enforced.

What's required: Every PLOS ONE submission must include a Data Availability Statement specifying where the data underlying all results in the manuscript can be accessed.

Acceptable data locations:

• Within the paper and its Supporting Information files
• In a public repository (Dryad, Figshare, Zenodo, GEO, etc.)
• Available upon request (only when legal or ethical restrictions apply)

What's not acceptable: "Data available upon request from the corresponding author" is not sufficient unless there are documented legal or ethical constraints. PLOS ONE expects data to be freely accessible.

This isn't a soft requirement. Papers have been rejected or retracted for failing to comply with PLOS ONE's data availability policy. If your data has access restrictions (patient identifiers, proprietary datasets), you need to explain the restriction clearly and provide a contact for data access requests.

Where it goes: The Data Availability Statement is entered into a separate field in the submission system, not in the manuscript body. It's published with the article in a prominent location.

PLOS ONE uses the term "Supporting Information" (not "Supplementary Materials" or "SI Appendix"). Supporting Information is published alongside the article and accessible to all readers.

Types of Supporting Information:

• S1 Fig, S2 Fig, etc.: Supporting figures
• S1 Table, S2 Table, etc.: Supporting tables (preferably in XLSX format)
• S1 File, S2 File, etc.: Supporting documents, datasets, code
• S1 Video, S2 Video, etc.: Video files
• S1 Text: Extended methods or additional narrative

Formatting rules:

• Each Supporting Information item is uploaded as a separate file
• Each item needs a title and a brief legend (entered in the submission system)
• In the main text, cite supporting items as "S1 Fig" not "Supplementary Figure 1"
• There's no page or file count limit, but each file has a 25 MB size cap
• For larger files, use a public repository and cite the DOI

Supporting Information is not peer-reviewed at PLOS ONE. This is different from journals like Cell Reports or Nature, where supplementary data undergoes full review. At PLOS ONE, reviewers may look at supporting files, but they're not required to evaluate them. This means the supporting information doesn't carry the same evidentiary weight as the main text.

Title page requirements (first page of manuscript):

• Full title
• Short title (running head, 40 characters max)
• Author names with affiliations (numbered superscripts)
• Corresponding author designation with email
• Author contributions
• No abstract on the title page (abstract goes on a separate page)

Cover letter is optional at PLOS ONE. This is different from selective journals where the cover letter is a critical part of the evaluation. PLOS ONE evaluates papers on scientific soundness, not perceived impact, so a cover letter arguing for significance isn't necessary. If you do include one, keep it brief.

These are the details that PLOS ONE regulars know:

No assessment of perceived impact. PLOS ONE reviews papers for scientific validity and methodological soundness, not for novelty or significance. This affects formatting indirectly: you don't need to spend word count arguing why your work is groundbreaking. Just present the science clearly.

Author contributions are mandatory. PLOS ONE requires that author contributions be listed using the CRediT taxonomy. Each author must be assigned at least one CRediT role: Conceptualization, Data Curation, Formal Analysis, Funding Acquisition, Investigation, Methodology, Project Administration, Resources, Software, Supervision, Validation, Visualization, Writing - Original Draft, Writing - Review & Editing.

Financial disclosure statement. Mandatory. Must list all funding sources and grant numbers. If there's no external funding, state "The author(s) received no specific funding for this work."

Competing interests statement. Mandatory, even if there are none. Use: "The authors have declared that no competing interests exist."

Ethics statement. Required for all studies involving human participants, animal subjects, or identifiable human data. Must include IRB/IACUC names, approval numbers, and consent procedures.

ORCID iDs. Required for all corresponding authors. PLOS ONE has progressively expanded its ORCID requirements.

Abbreviations. Define at first use in both the abstract and the main text. PLOS ONE provides a list of standard abbreviations that don't need definition (DNA, RNA, PCR, etc.).

Heading structure. PLOS ONE uses the standard IMRAD structure: Introduction, Materials and Methods, Results, Discussion. Subheadings within each section are allowed and encouraged for readability.

No footnotes. PLOS ONE doesn't allow footnotes in the main text. All clarifying information should be incorporated into the text or placed in Supporting Information.

1. Separate files from the start. PLOS ONE requires separate manuscript and figure files at initial submission. No single-PDF submissions.

1. Figure file naming. Files must be named Fig1.tif, Fig2.tif, etc. Not "Figure_1_final_v3.tif" or any other creative naming scheme.

1. Data Availability Statement goes in the submission system. It's not in the manuscript body. Authors who put it in the manuscript but skip the submission system field will be flagged.

1. DOIs in references. Include them for every reference that has one. PLOS ONE checks this during technical review.

1. No footnotes. This catches authors who habitually use footnotes for definitions or asides.

1. CRediT taxonomy for author contributions. Free-text descriptions of author roles aren't accepted. Use the specific CRediT role terms.

1. Short title is 40 characters max. Not 40 words. Characters. This is tight. Plan accordingly.

1. Line numbers. Required. Continuous numbering throughout the manuscript.

PLOS ONE is fully open access under a CC BY 4.0 license. An article processing charge (APC) is required upon acceptance.

The current PLOS ONE APC is approximately $1,900. This is lower than most high-profile open-access journals (Science Advances charges roughly $4,500, for comparison). PLOS offers fee assistance programs for authors who can't pay, and ability to pay never influences editorial decisions.