Kobo rejected 45% of self-published books last year, mostly over AI

What happened

Rakuten Kobo rejected 45% of self-published books submitted through its Kobo Writing Life platform in 2025. More than 80% of those rejections stemmed from content that Kobo’s chief executive, Michael Tamblyn, identified as obviously AI-generated. This marks a significant tightening of content standards for self-published authors on a platform designed to say yes.

Why it matters

Kobo’s sharp increase in rejections pressures the self-publishing ecosystem to rethink how AI-generated writing fits within digital book marketplaces. Many authors and small publishers rely on such platforms for distribution without gatekeeping. Kobo’s approach signals rising distrust around AI content quality and potential copyright or originality issues. This raises the bar for self-publishing authors to demonstrate genuine human contribution or creative input, not simply AI output repackaged as new work.

For operators running platform businesses, the move underscores growing challenges in managing AI content at scale. It exposes the risks of flooding marketplaces with low-quality or derivative AI writing, which can damage trust and user experience. Kobo’s decision allocates resources to content vetting and sets precedent for other platforms facing similar pressures. For authors, this means higher rejection risk and more scrutiny of content provenance.

What to watch next

Watch how other self-publishing platforms respond. Will rivals enforce similar restrictions or offer more lenient policies to attract AI-assisted authors? The balance of supply and quality control is likely to become a competitive factor. Also track how AI content detection technologies evolve as platforms try to identify machine-generated writing without false positives.

Beyond publishing, regulatory or industry responses to AI-produced content may emerge, affecting platform liability or authorship rules. For operators, this signals the need to build scalable content review and policy enforcement systems that address AI content’s unique challenges while avoiding unnecessary barriers to legitimate creators.

AI Quick Briefs Editorial Desk