A new preprint platform is paying scientists to review other researchers’ work, reviving a debate over whether peer review should be compensated. XSci, launched in September, offers reviewers $200 for feedback submitted within five days of accepting an assignment, or $100 for feedback submitted within five to 10 days. The Delaware-based startup says its service could give authors rapid feedback while helping address the growing difficulty of finding willing reviewers.
Inviting researchers to review papers is considered a potential solution to clearing the review backlog.Credit: UpPiJ/iStock (via Getty)
The fees are paid by researchers who use XSci to obtain peer reviews of their preprints. XSci does not publish journals. Instead, it charges authors $399 for one peer review or $249 to publish a peer-review report.
“Answers to the questions authors are most interested in are usually available within five to 10 days: Does this paper really have a chance of being published in the journal I’m aiming for? Currently, those answers can take months, and in some fields even years,” says Shumiao Ouyang, an economist at the University of Oxford, UK, and XSci’s founder.
XSci also charges authors up to $19 to have preprints assessed by various artificial-intelligence programs, although some AI tools are available free of charge. Ouyang says the company has received about $500,000 from private investors and is seeking additional funding.
A publishing platform that puts your code front and center
Researchers interviewed by Nature said that XSci’s business model was interesting, but that its future would depend largely on whether it could persuade authors to pay for human peer review.
“Are authors willing to pay such fees? Where will the money come from?” asks Daniel Gorelick, a developmental biologist and toxicologist at Baylor College of Medicine in Houston, Texas. He also said that cash payments are a “strong incentive”.
Biology Open, an open-access journal published by The Company of Biologists, has paid reviewers £220, or $280, per manuscript since 2024 through a programme called Fast and Fair. Reviewers receive payment when they submit their work on time and the quality meets the editor’s expectations.
Ouyang expects XSci’s main users to be doctoral and postdoctoral students and other early-career researchers who “often cannot wait more than a year for a journal decision.”
Pay per review
Researchers have traditionally been expected to review manuscripts as a service to the scientific community rather than for a fee. Ouyang says that paying reviewers at the preprint stage could help address a major problem in academic publishing: persuading researchers to review other scientists’ work, and to do so promptly.
Studies1–3 have shown that journal editors are finding it increasingly difficult to recruit reviewers. The causes include rising numbers of manuscript submissions and growing workloads for academics. These pressures can produce review times ranging from weeks to months.
XSci’s website says that researchers interested in becoming paid reviewers can register. In practice, however, Ouyang says that reviewers must be invited through the platform to assess individual manuscripts. The site’s “Register Interest” field remains useful, he says, because it shows how many motivated researchers there are in each field.
Shumiao Ouyang is an economist at the University of Oxford, UK, and founder of XSci.Credit: Yizhen Zhang
Ouyang says XSci has developed an AI system to identify suitable reviewers quickly. When an author uploads a manuscript and chooses human review, the system screens potential candidates from three sources: scientists who wrote papers cited in the manuscript, the cited researchers’ regular collaborators, and researchers who have published similar work in the author’s target journal.
The system ranks potential reviewers and contacts them by email. Each candidate has 12 hours to accept the assignment, Ouyang says.
If reviewers conclude that a manuscript could be publishable in the author’s target journal after reasonable revisions, XSci adds a badge to the preprint indicating that it has been peer reviewed and approved by the reviewers.
XSci eventually hopes to work with journal publishers so that editors can consider its peer-review reports during their evaluations. This would happen only if both authors and reviewers agreed to share the reports, Ouyang says. Editors could decide whether to use an XSci review instead of one round of their own review or as an external reference.
However, Ouyang emphasized to Nature that the badges are only “useful information for editors”.
“Whether a journal gives weight to them or not is entirely a journal decision,” he added.
Advantages and disadvantages
In 2025, the Fast and Fair programme at Biology Open substantially reduced the time editors took to reach an initial decision, according to a preprint co-authored by Gorelick. The average fell to 5.5 business days, compared with 37.7 business days through the journal’s unpaid review route.4 The study also found higher rates of acceptance of review invitations and completion of accepted assignments.
Other research has found more limited benefits. Editors at Critical Care Medicine, a journal published by Lippincott, Williams & Wilkins, conducted a six-month experiment in which reviewer invitations alternated every two weeks between those offering financial incentives and those offering no fee.5
Half of the invitations offering a $250 cash reward resulted in a peer-review report within 14 days, compared with 42% of invitations without a fee. Paid reviewers completed their work an average of one day faster.
“It didn’t move the needle very much,” says David Maslove, a clinician and scientist at Queen’s University in Kingston, Canada, and a co-author of the study.
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Researchers also warn that paid systems bring risks. Gorelick says that strict quality controls and clear policies will be needed to prevent reviewers from abusing the system and publishers from exploiting reviewers. “You can’t just pay a reviewer and walk away,” he says.
“XSci currently does not check the quality of reviews performed by peer reviewers before making them available to authors,” says Jeffery Poon, XSci’s publishing and editorial director. Authors who are dissatisfied with a review can file a dispute through XSci, Poon says. The company plans to offer tools that will help reviewers check their work, although the team is still considering how those tools should be implemented.
Source: www.nature.com
