What are preprints?
Last updated on March 27, 2026
Preprints are preliminary versions of scholarly or scientific manuscripts that precede publication in a peer-reviewed journal and act as an early indication of research.
Preprints reside on preprint servers, which cover a set of domains and allow for dissemination, laying claim to an idea, and help collect feedback prior to submission. In some fields, preprints are the main communication vehicle. Preprints differ from Articles-in-Press in that preprints are not peer-reviewed and are not accepted for publication in a journal.
Currently, preprints are available in the Compendex and Inspec databases.
You may limit your search query to only preprints from the Compendex and/or Inspec databases as follows:
- From the Document results list after running a Quick search query, select the ‘Preprint’ checkbox for Document type.
- From the Expert search form, enter the following search query using the ‘pp’ search code with the DOCUMENT TYPE (DT) search field.
- (pp wn DT)
Example:
("solar collector" wn TI) AND (pp wn DT)
Alternately, you may exclude preprints from Expert searches from the Compendex and/or Inspec databases:
- Add the following search phrase to your Expert search query:
- NOT (pp wn DT)
Example:
("pandemic" wn KY) NOT (pp wn DT)
Note: If preprints are available for your search query, you will see a message at the top of your search results notifying you that they are included in your search results. This message will refer you to this help FAQ to learn how to exclude them from your search results if you do not want them included. Refer to the instructions above to exclude them from a search query or to the Refine search results to exclude preprints section below to remove them from your results using the ‘Document type’ facet.
You may refine your Compendex and/or Inspec search results to be limited to preprints:
- Conduct a Quick or Expert search. The Document results list displays.
- From the ‘Document type’ facet in the ‘Refine’ results pane, select ‘Preprint.’
- Click ‘Limit to.’ The Document results list refreshes to display only preprint documents.
You may refine your Compendex and/or Inspec search results to exclude preprints:
- Conduct a Quick or Expert search. The Document results list displays.
- From the ‘Document type’ facet in the ‘Refine’ results pane, select ‘Preprint.’
- Click ‘Exclude.’ The Document results list refreshes to exclude all preprint documents.
Preprints in Compendex currently come from four selected preprints servers: ‘arXiv,’ ‘Research Square,’ IEEE's ‘TechRxiv,’ and the ‘Applied Sciences and Physical Sciences’ collections from ‘SSRN.’ The preprints in Inspec come from the arXiv preprint server.
Yes, all preprints are Open Access and therefore, they are freely accessible. Click the ‘Full text’ button for the preprint on the Document Results list or the record page to access the corresponding preprint full-text record.
The further back in time that a preprint is posted in a repository, the less likely an author is currently conducting research associated to it. Compendex and Inspec can more accurately provide an early indication of research by focusing on more recent years. Most preprints that were posted before 2017 have either already become published articles or are not likely to be published.
Preprints are not peer-reviewed and no endorsement of the methods, assumptions, conclusions, or scientific quality is implied by the preprint server, Compendex, Inspec, or Engineering Village. Some preprint servers may have a basic screening process for offensive or non-scientific content, material that might pose a health or security risk, and for appropriateness to the scientific subject field of the preprint server.
The Accession number for preprint documents differs from those assigned to the other content in Compendex, but the reason for this difference is purely internal/operational. There is no meaning to be derived from, attributed to, or understood from the structure of the Accession number for preprints, other than that the first four digits indicate the production year, as in YYYY0000000 (e.g., 20260123456).
Preprints may ultimately be published in a journal. If the research work exists as both a preprint and as a publication, the preprint exists in parallel with the published article. Therefore, the preprint and the published article are two separate entities which are similar (but not identical) and both exist in Compendex and/or Inspec. Preprints versioning is proactively managed to include only the most recent version of a preprint in Compendex and/or Inspec. The possibility of linking preprints to the corresponding published version of record (if available) is currently being evaluated.
Preprints in Compendex and Inspec are not deleted. Preprints are maintained to provide uniformity and to keep the scientific documentation. Although a published article may result from the same research as a preprint record, they are two separate entities with their own content and quality values. Some preprints will never be published, but they will be kept in Compendex and Inspec to maintain the research documentation described in the preprint record.
Did we answer your question?
Related answers
Recently viewed answers
Functionality disabled due to your cookie preferences