In late 2023, Wikipedia editors identified a growing influx of AI-generated content characterized by repetitive phrasing. This led to the creation of the WikiProject AI Cleanup, an initiative dedicated to removing machine-generated material. Founding member Ellia Lebleu noted that early AI contributions were easily detectable, but by 2025, the patterns had evolved into subtler structural markers, such as the frequent use of the "rule of three."
The proliferation of AI-generated citations has emerged as a major concern. While outright hallucinations have decreased, instances where real sources are misinterpreted remain commonplace. In response, English Wikipedia implemented a prohibition against using large language models to draft articles. An AI-detection company estimated that 20 percent of new articles and drafts were flagged as AI-generated in late 2025, a figure that declined to 15 or 16 percent in early 2026.
To counter this trend, Wikipedia is deploying AI-assisted tools for verification. These include an AI source verifier and Paste Check, a tool designed by the Wikimedia Foundation to flag text directly copied from chatbots. Discussions continue regarding Wikipedia's identity as a human-written encyclopedia and the potential future role of AI in contributing to the site's repository of knowledge.