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On 5 July 2025, the weekend edition of Germany's Frankfurter Allgemeine Zeitung published the article "Wikipedia weiß immer weniger" ("Wikipedia knows less and less", archive (not paywalled)). The newspaper examined a random sample of over 1,000 German-language Wikipedia articles for potential errors and found problems on more than a third of the pages in their sample – in particular, outdated articles. The number of Levi Strauss & Co. shops, for example, dated from 2009, the paper said, and was badly out of date, as the number had since grown to "more than 1,000, according to the latest annual report" (or more than 3,400, if you believe the English Wikipedia article's infobox). Even Sweden's tallest mountain had changed, as ice on the southern peak of Kebnekaise had melted, meaning it was now lower than the northern peak (English Wikipedia had the correct information, noting the melt).

The Frankfurter Allgemeine team provided a description of their methodology and the full list of articles they examined, complete with indications of any issues found: "So haben wir Wikipedia geprüft" ("This is how we checked Wikipedia", archive). The team used a methodical approach, starting with the "random article" function. As heise online summarised the method in an English-language write-up of the study, the paper then checked the articles as follows:

According to the report, the team of reporters first checked the texts for anomalies using AI. Subsequently, internal archive documenters are said to have scrutinized the findings once again. The report goes on to say that only when two of the human reviewers were convinced that a piece of information was incorrect did the corresponding article end up on the list of defects. The analysis revealed that more than every third page was problematic. At least 20 percent of the entries contained information that was "no longer up to date". Only half of these were immediately apparent to users. In addition, there are "almost as many pages with information that has never been correct". Wikipedia itself displays a notice on around 8,000 pages that a page is not up-to-date. However, the random sample suggests that this warning should be displayed on more than 600,000 articles.

The Frankfurter Allgemeine article noted that studies referred to by Wikimedia as evidence that Wikipedia was equal or better than commercial encyclopedias or textbooks are by now quite long in the tooth, mostly dating back to the early 2000s. The 2005 Nature study is still often cited as evidence that the English-language Wikipedia is comparable in quality to the online Britannica even though it is almost 20 years old, included only 42 articles in the study, and found that there were only 123 errors in the Britannica articles compared to 162 in the Wikipedia articles (see The Signpost's 2005 coverage).

Frankfurter Allgemeine readily admitted that "AI is often wrong, too" and that AI is not yet ready to replace Wikipedia. The paper quoted an external commentator, Leonhard Dobusch (User:Leonidobusch, professor of organizational science at the University of Innsbruck), who suggested that the WMF could easily pay around 50 editors to keep articles up to date, given that updating the stock of articles across the board does not seem to work. However, Dobusch also pointed out that articles that suddenly become interesting are usually improved quickly. Then again, Frankfurter Allgemeine found that almost 90 per cent of all page views were accounted for by the 99% of articles that are not currently in the public spotlight – precisely because every user is interested in something else.

The Frankfurter Allgemeine study led to voluminous discussions on the talk page of the German Wikipedia's Signpost equivalent, the Kurier, with the thread well beyond 50,000 words at the time of writing. Topics discussed include the role of Wikidata, whether or not articles have become too long, and the basic quandary of fewer volunteers – about half as many as in 2008 – having to look after an ever increasing number of articles – now in excess of three million, about four times as many as in 2008. Dobusch himself participated briefly, explaining his maths as being based on an annual budget of €5 million. A Wikimedia Germany representative clarified that paying editors for article maintenance work was not a realistic proposition and was not being considered.

German Wikipedia contributors generally welcomed the provision of the complete article list, which was copied to a user page. Progress on checking and where necessary fixing the issues is ongoing and being tracked. At the time of writing, around a quarter of the issues have been addressed; community members assert that most of the major issues have been checked, and where appropriate fixed. An article in Netzpolitik by Dobusch commented positively on the clean-up effort and the public discussion.

Another English-language write-up of the study appeared on Axel Springer SE-owned TECHBOOK (also syndicated on Yahoo News), arguing that the issue of outdated or incorrect articles –

gains additional urgency in the age of AI-powered chatbots. Many of these systems use Wikipedia as a basis to generate answers to user questions.

This is a valid concern, though it should be noted that the importance of Wikimedia wikis in training large language models is often overstated (see last week's Signpost issue).

Lastly, not all the issues raised by the Frankfurter Allgemeine team were found to be valid; a community member pointed out, for example, that notwithstanding the newspaper's claim, the A99 road really does continue past the point where it meets the A836 and leads all the way to the place where the ferry to Burwick departs in the summer months. In another intriguing case, a discrepancy in the birth year of Angelica Balabanoff turned out to be based on the fact that a biography published in 2016 asserted that Balabanoff had given multiple different birth dates over the years and had made herself younger, possibly to cover up an early failed marriage in Russia; the German biography now contains a paragraph on the claim, along with the more widely cited birth year.

– AK, S