---
title: "ArXiv"
chunk: 1/2
source: "https://en.wikipedia.org/wiki/ArXiv"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:48:34.832856+00:00"
instance: "kb-cron"
---

arXiv (pronounced as "archive"—the X represents the Greek letter chi ⟨χ⟩) is an open-access repository of electronic preprints and postprints (known as e-prints) approved for posting after moderation, but not peer reviewed. It consists of scientific papers in the fields of mathematics, physics, astronomy, electrical engineering, computer science, quantitative biology, statistics, mathematical finance, and economics, which can be accessed online. In many fields of mathematics and physics, almost all scientific papers are self-archived on the arXiv repository before publication in a peer-reviewed journal. Some publishers also grant permission for authors to archive the peer-reviewed postprint. Begun on August 14, 1991, arxiv.org passed the half-million-article milestone on October 3, 2008. By the end of 2014, it had surpassed one million articles, and it reached two million by the end of 2021. As of November 2024, the submission rate is about 24,000 articles per month.

== History ==

arXiv was made possible by the compact TeX file format, which allowed scientific papers to be easily transmitted over the Internet and rendered client-side. Around 1990, Joanne Cohn began emailing physics preprints to colleagues as TeX files, but the number of papers being sent soon filled mailboxes to capacity. Paul Ginsparg recognized the need for central storage, and in August 1991 he created a central repository mailbox stored at the Los Alamos National Laboratory (LANL) that could be accessed from any computer. Additional modes of access were soon added: FTP in 1991, Gopher in 1992, and the World Wide Web in 1993. The term e-print was quickly adopted to describe the articles.
It began as a physics archive, called the LANL preprint archive, but soon expanded to include astronomy, mathematics, computer science, quantitative biology and, most recently, statistics. Its original domain name was xxx.lanl.gov. Due to LANL's lack of interest in the rapidly expanding technology, in 2001 Ginsparg changed institutions to Cornell University and changed the name of the repository to arxiv.org.
Ginsparg brainstormed the new name with his wife; the domain "archive" was already claimed, so "chi" was replaced with "X" standing in as the Greek letter chi and the "e" dropped for symmetry around the "X".
arXiv was an early adopter and promoter of preprints. Its success in sharing preprints was one of the precipitating factors that led to the later movement in scientific publishing known as open access. Mathematicians and scientists regularly upload their papers to arxiv.org for worldwide access and sometimes for reviews before they are published in peer-reviewed journals. Ginsparg was awarded a MacArthur Fellowship in 2002 for his establishment of arXiv. The annual budget for arXiv was approximately $826,000 for 2013 to 2017, funded jointly by Cornell University Library, the Simons Foundation (in both gift and challenge grant forms) and annual fee income from member institutions. This model arose in 2010, when Cornell sought to broaden the financial funding of the project by asking institutions to make annual voluntary contributions based on the amount of download usage by each institution. Each member institution pledges a five-year funding commitment to support arXiv. Based on institutional usage ranking, the annual fees are set in four tiers from $1,000 to $4,400. Cornell's goal is to raise at least $504,000 per year through membership fees generated by approximately 220 institutions.
In September 2011, Cornell University Library took overall administrative and financial responsibility for arXiv's operation and development. Ginsparg was quoted in the Chronicle of Higher Education as joking that it "was supposed to be a three-hour tour, not a life sentence". However, Ginsparg remains on the arXiv's Scientific Advisory Board and its Physics Advisory Committee.
In January 2021, arXiv was declared as one of the “10 computer codes that transformed science” by the Nature journal. In January 2022, arXiv began assigning DOIs to articles, in collaboration with DataCite.
In March 2026, arXiv announced that it would separate itself from Cornell University and become an independent nonprofit organisation on July 1, 2026. The split was motivated by a desire to diversify and increase arXiv's funding.

== Data format ==
Each arXiv paper has a "uniquely specific identifier":

YYMM.NNNNN, e.g. 1507.00123,
YYMM.NNNN, e.g. 0704.0001,
arch-ive/YYMMNNN for older papers, e.g. hep-th/9901001.
Different versions of the same paper are specified by a version number at the end. For example, 1709.08980v1. If no version number is specified, the default is the latest version.
arXiv uses a category system. Each paper is tagged with one or more categories. Some categories have two layers. For example, q-fin.TR is the "Trading and Market Microstructure" category within "quantitative finance". Other categories have one layer. For example, hep-ex is "high energy physics experiments".