Preprints publishes articles from all fields of research that report scientifically sound original research or present a comprehensive review of a field. The following types of articles are generally suitable: Article, Review, Conference Paper, Data Descriptor, Essay, Brief Report, Case Report, Communication, Short Note, Technical Note, Hypothesis. Other article types may be accepted at the discretion of the editorial team. We typically do not permit editorials, discussion papers or coursework.

Preprints must not have appeared in a peer-reviewed venue, such as a journal or conference proceedings. We recommend against posting the same paper to multiple preprint servers.

All authors must be fully aware of the submission to Preprints and agree. All and only those that qualify for authorship must be included as authors. We recommend referring to the ICMJE recommendations about authorship and the Credit taxonomy.

ORCIDs are standard, persistent identifiers for authors. We encourage all authors to link their ORCID with their Preprints account during the submission process.

While most journals accept preprint submissions, some may not. We recommend checking all journals you will potentially submit to. The best places to check are the journal website and the Sherpa Romeo database.

If you intend to register a patent based on the work, do not post a preprint as it will compromise your application.

Preprints adheres to the Committee on Publication Ethics (COPE) Code of Conduct and Best Practice Guidelines. Note that COPE does not currently cover preprints specifically, but many of the same principles apply, including the following:

• Authors must accurately present their research findings and include an objective discussion of the significance of their findings.
• Plagiarism, data fabrication and image manipulation, knowingly providing incorrect information, copyright infringement, inaccurate author attributions, attempts to inappropriately manipulate the screening process, failures to declare conflicts of interest, fraud, and libel are not permitted.
• Manuscripts containing research conducted on humans or experimental animals must follow the Declaration of Helsinki and contain details of approval from a research ethics committee. At a minimum, the project identification code, date of approval and name of the ethics committee or institutional review board should be cited in the "Methods" section.
• Informed consent of research participants must be obtained where necessary and authors must be able to provide a (redacted) copy of the consent form.
• Any facts that might be perceived as a possible conflict of interest of the author(s) must be disclosed in the paper prior to submission.
• Posting of submitted materials must not be illegal.

Preprints will rigorously enforce its standards and will follow up on cases of infringement. In extreme cases we may call on individuals to be reported to their institutions. Any complaints should be directed to info@preprints.org.

Preprints applies the ICMJE definition of a conflict of interest: “A conflict of interest exists when professional judgment concerning a primary interest (such as patients’ welfare or the validity of research) may be influenced by a secondary interest (such as financial gain). Perceptions of conflict of interest are as important as actual conflicts of interest.”

It is essential that authors obtain permission to reproduce any published material (figures, schemes, tables or any extract of a text) that does not fall into the public domain or for which they do not hold the copyright. The authors must request permission from the copyright holder prior to posting to Preprints.

Permission is required for:

• Your own works published by other publishers and for which you did not retain copyright.
• Substantial extracts from anyone's works.
• Use of tables, graphs, charts, schemes and artworks, if they are unaltered or with minor changes.
• Photographs for which you do not hold copyright.

Permission is not required for:

• Reconstruction of your own table with data already published elsewhere. Please notice that in this case you must cite the source of the data in the form of either "Data from..." or "Adapted from...".
• Short quotes that are considered fair use and therefore do not require permission; these must also be properly cited.
• Graphs, charts, schemes and artworks that are completely redrawn by the authors and significantly changed beyond recognition.

All preprints are posted using an open access Creative Commons CC BY 4.0 license. This means that the work can be freely downloaded, distributed and reused, provided that the author and preprint are cited in any reuse. This allows the maximum visibility for the work, while recognizing authors.

All authors must agree to the following:

• I grant Preprints a perpetual, non-exclusive license to distribute this article.
• I certify that I have the right to grant this license.
• I understand that submissions cannot be completely removed once accepted by Preprints and may appear on websites other than Preprints.

It is important that all authors understand that preprints cannot be removed once posted. Once a digital object identifier (DOI) is registered, information about the preprint is permanently available. In addition, a number of databases collect information about posted preprints.

Articles may be edited or deleted up until the time that they are submitted and announced. From that time on, articles will only be removed at the discretion of Preprints editors and the advisory board and for the following reasons:

• Misconduct by authors, including plagiarism and data fabrication.
• Serious scientific errors that cannot be corrected by updating the paper.
• Where leaving a paper online would constitute an illegal act, including copyright violation.

Preprints reserve the right to remove preprints without notice where there is sufficient reason for doing so.

Note that preprints can be updated by authors at any point and we do not consider rejection from a journal sufficient grounds for removal. Preprints will not be removed to allow journal submission, authors should check in advance whether the journal they intend to submit to accepts preprints.

Any style is allowed for submitted papers, however all publisher and journal logos and names should be removed. The first page of your manuscript must contain: title, author list, abstract, keywords, corresponding author contact details, and affiliations for all authors.

In order to facilitate author identification, authors should use institutional email addresses (e.g. provided by a university) where possible, or email addresses used in previously published papers. We recommend the use of ORCID identifiers.

Files should be submitted in Microsoft Word or LaTeX format. For LaTeX files, ensure that all files necessary to recreate the PDF are included in a zip or similar archive.

To ensure readability and clarity, we recommend producing a graphical abstract to display on the website alongside the textual abstract. The graphic should be provided as a JPG, PNG or GIF file.

Preprints must include a comprehensive bibliography showing link to recent research and, if reporting original experimental research, have the structure of a research article (introduction, methods, results and discussion).

Once you have carefully checked the criteria above, click the “Submit preprint” button on the upper right corner of the website to submit your manuscript. You will need to have a Preprints account and log in to submit.

Authors submitting to MDPI journals have the option to submit to Preprints during journal submission.

The corresponding author’s roles and responsibilities are as follows:

1. Inform all co-authors of the submission to Preprints (note: each co-author will receive a confirmation email upon submission).
2. Manage correspondence between Preprints and co-authors, keeping the full co-author group informed throughout the submission, announcement, and update process.
3. Ensure that all co-authors understand Preprints' policies (including such items as publication ethics, data and supplementary material deposition, conditions for withdrawal, copyright, licenses).
4. Take full responsibility for answering questions/comments regarding the announced preprint, as well as providing data or materials requested.

In order to maintain transparency and integrity, Preprints requires that authors make all data associated with their submission available where there are no legal or confidentiality constraints in doing so. We encourage authors to follow FAIR data principles, and upload data to a recognized data repository before posting a preprint (such as one from Re3data). Authors can also upload supplementary materials in any format along with their preprint (up to 50 MB per file).

Links to data hosted externally to Preprints can be added during submission.

Once you have submitted your preprint, there will be a screening process that typically takes 24 hours (one working day). If any further information is required, you will be contacted by an editor.

If you are interested in helping to screen preprints, see here.

You can manage all of your articles in your user profile dashboard. There are five submission statuses: Incomplete, Pending Approval, Online, Withdrawn and Rejected.

Incomplete: Your submission is in process when it is in this status, but not yet submitted. It may still be edited up until the submission. At this point the preprint will not be publicly available. Submissions left incomplete for 14 consecutive days will be deleted from Preprints.

Pending approval: Your submission is undergoing the internal editorial check. In most cases, this will take less than 24 hours and no action is required from the authors.

Online: Your submission has passed the editorial check, is now online, and is open for public peer review.

Withdrawn: Your withdrawn submissions.

Rejected: Submissions that were rejected by Preprints editorial office.

A feature of preprints is that they can be updated by authors at any time. We recommend that you inform colleagues and others working on similar topics about your preprint. If they provide feedback and you would like to update your preprint, go to your online preprints and click ‘Submit follow-up version’.

Preprints is cooperating with MDPI Topics. MDPI Topics in Preprints is a service offered to authors who want to submit to a MDPI journal after posting their paper on Preprints. It means that authors who submit their papers to MDPI Topics via Preprints may be invited to contribute to a relevant journal of MDPI Topics.

Papers of users who select “MDPI Topics” while submitting their manuscript via Preprints’ system are posted on Preprints. The users may benefit from the following:

iThenticate Plagiarism Check: The plagiarism check generates a report that highlights any instances of text duplication and potential plagiarism, along with advice on where to modify text or add further citations;

Layout Editing: Layout editing prepares your submission for publication based on the MDPI journal template;

Journal Recommendation: Our in-house editor will invite you to contribute to a relevant journal of MDPI Topics. Once you accept their invitation, the submission information of your article will be transmitted from Preprints to the submission system of MDPI journals, which reduces the time it takes for your submission to be processed.

It is very simple! Just select the “MDPI Topics” option when you submit your next article in the step of submission via Preprints. Click here to submit.