An e-print archive, founded by Paul Ginsparg in 1991 and maintained and operated by Cornell University. It is a free distribution service and an open-access archive for close to 2,367,795 pre-peer-reviewed scholarly articles in the fields of physics, mathematics, computer science, quantitative biology, quantitative finance, statistics, electrical engineering, systems science, and economics.

The bioRxiv, operated by Cold Spring Harbor Laboratory, is a fairly new but growing open archive for more than 214,755 unpublished preprints in the life sciences. The bioRxiv provides free and unrestricted access to all articles posted on the server.

CERN Document Server is collections of various openly available documents of nearly 579,127, among which over 139,086 are preprints related to particle physics and related areas. In addition to preprints, this server also provides access to articles, books, and proceedings.

A new but fast-growing archive for unpublished preprints which provide free submission and distribution of articles in Chemistry and related areas. This platform with a collection over 20,887 helps the researcher to collect feedback and recommendations on their preprints.

ChinaXiv, maintained and operated by National Science Library, Chinese Academy of Science is a preprints archive and open repository for scientific unpublished articles in the field of natural science. There are also several sub-domains of this platform like PsyChinaXiv Preprints, ChinaXiv Biology Preprints, and many more.

An electronic archive of more than 4,230 scientific manuscripts is a platform for self-archiving papers in any area of Psychology, Neuroscience, Linguistics, Computer Science, Philosophy, Biology, Medicine, and Anthropology. It also archives papers in certain areas of physical, social, and mathematical sciences.

The Earth and Space Science Open Archive (ESSOAr) is a community server with 13,468 public documents, developed by American Geophysical Union (AGU) and Atypon established to accelerate the open discovery and dissemination of earth, environmental, and space science research by archiving and sharing early research outputs, including preprints, presentations from major scientific meetings, and important documents of scholarly societies.

A multidisciplinary preprint archive active since 2017 publishes articles from all subdomains of Earth Science and related domains of planetary science. EarthArXiv platform assigns each submission a Digital Object Identifier (DOI) and so far hosting more than 4,213 manuscripts related to the domain. It is being hosted by California Digital Library since its establishment.

A preprint service for electrochemistry and solid-state science and technology operated by ECS (Electrochemical Society) and powered by OSF.

The engrXiv launched in 2016 at the University of Wisconsin-Stout and the server is operated by Open Engineering Inc. The server holds nearly 3,000 scientific research papers in the subject domain of engineering and is dedicated to the dissemination of engineering knowledge quickly and efficiently.

E-LIS was established in 2003 and hosted by the Library System of the University of Naples Federico II. Now it is the largest international open repository in the field of library and information science having over 24,940 documents.

TThe medRxiv is a free online archive and distribution server for preliminary reports of work that have not been certified by peer review in the medical, clinical, and related health sciences. The medRxiv was founded by Cold Spring Harbor Laboratory (CSHL), a not-for-profit research and educational institution, Yale University, and BMJ, a global healthcare knowledge provider. It holds nearly 48,134 pre-peer reviewed documents.

The Open Science Framework (OSF) is an initiative of Centre for Open Science- a leading preprint service providers offer this open-source infrastructure to support their communities. OSF Preprints is an open-source system which enables many other preprints service providers (over 25) to create preprint server and disseminate their services. This serves as single point discovery tool (Metasearch) for over a collection of 2,435,000 preprints.

The PhilArchive is the largest open-access e-print archive for works on philosophy developed and operated by the Centre for Digital Philosophy at Western University. There are currently 86,068 works in the archive. These works fall under 5,858 topics.

PsyArxiv, maintained by The Society for the Improvement of Psychological Science, is a free preprint service for the psychological sciences that contains more than 32,470 research articles.

RePEc is the world’s largest database of economics and related science research documents. Researchers can explore economic literature on two RePEc services i.e. On EconPapers and IDEAS. On EconPapers 1,182,574 Working Papers (1,001,034 downloadable) in 5,592 series and 3,112,795 Journal Articles (3,042,160 downloadable) in 4,102 journals have been listed. Notably, based on RePEc, IDEAS indexes over 4,600,000 items of research, including over 4,100,000 that can be downloaded in full text.

SocArXiv is an open archive for research of Social Science, is part of the University of Maryland, which includes more than 13,730 research articles of Arts and Humanities, Education, Law and Social and Behavioural Science. SocOpen.org is its official blog and information center.

The TechRxiv is is an open, moderated preprint server for unpublished research in the areas of engineering, computer science, and related technology. This is powered by IEEE and already has more than 8,100 preprints.