The world’s biggest preprint server has put a speed limit on science publishing. Here is what changed and why.

Starting October 1, arXiv limits every author to two paper submissions a month, with no more than three active submissions at a time. A rejected paper still counts against the monthly total.

The reason is volume. arXiv received 40,363 submissions in September, a record, up from 20,569 in September 2024. Submissions in computer science AI have risen more than sixfold in two years.

Advanced AI tools have made it trivial to generate plausible-looking papers in minutes. arXiv says a small number of authors are flooding the server with low-quality papers, overwhelming volunteer moderators.

This is unfair to authors who continue to submit quality papers, said Thomas Dietterich, chair of arXiv’s editorial advisory council. Their papers can be delayed for days or weeks.

arXiv’s policy allows AI as a research tool if disclosed, but many submissions do not meet its standards.

Why it matters: the limit is the clearest sign yet that AI-generated paper spam is straining the infrastructure of science itself.