“Most readers assume Wikipedia is a reliable online encyclopedia, but in reality,it has become a biased platform manipulated by agenda-driven editors on many topics,” said Jonathan Greenblatt, CEO and national director of the ADL. “Recent Wikipedia efforts toward neutrality are nothing but a Band-Aid on a problem that’s getting worse, with persistent antisemitic and anti-Israel bias still far too present.”

In its research, the ADL found “clear evidence” that a group of some 30 editors coordinated to deliberately “introduce antisemitic narratives, anti-Israel bias and misleading information,” the report stated. They discovered these editors were over twice as active on the site compared to other Wikipedia editors and communicated with each other 18 times more when compared to other editor group communications. The ADL also found that edits increased dramatically following the Hamas-led terror attacks in southern Israel on Oct. 7, 2023.

“We urge Wikipedia and policymakers to act quickly before rampant disinformation on one of the most visited sources of information leads to tragic consequences,” Greenblatt said.

Additionally, the report found evidence of extremist, pro-Hamas content in the Arabic-language edition, as Wikipedia’s rules are not applied consistently outside of some English-language pages.

“It’s clear that Wikipedia needs to do far more to address the very active antisemitic and anti-Israel bias and coordination,” said Daniel Kelley, interim head of the ADL Center for Technology and Society. “And until then, other platforms that rely on Wikipedia as a source—from Google Search to large language models like ChatGPT—must deprioritize Wikipedia’s content on issues related to Jews, Israel and the Middle East conflict so they do not perpetuate this bias.”