ChatGPT’s GPT-5.5 update significantly altered citation patterns in German-language responses, favoring local sources and Reddit while diminishing global aggregators, according to a new analysis.
The shift, identified by search engine optimization firm SISTRIX, indicates a move toward localization in the artificial intelligence model’s output for German queries, impacting various online platforms.
SISTRIX analyzed 3.8 million German-language ChatGPT responses and found daily variations in citation patterns surged from 1 to 2 percent to 47 percent during a model-identifier change between May 22 and May 23.
The average number of cited sources per response also decreased after the update, falling from 30.9 to 28.4, SISTRIX reported.
Reddit experienced the largest absolute gain, with citations increasing by 59 percent. German mainstream publishers such as Welt.de, faz.net, and bild.de, along with streaming and sports platforms like Dazn.com, sky.de, and kicker.de, also saw significant increases in citations.
Conversely, international aggregator platforms, including Indeed, Tripadvisor, Glassdoor, Expedia, and Rome2rio, recorded the steepest declines in citations. Global tech platforms like YouTube, Wikipedia, Google.com, Facebook, and LinkedIn also saw their citation frequency drop.
Johannes Beus, CEO of SISTRIX, said in a statement that the data suggests a clear pattern of ‘localization,’ where more German-language sources appeared in responses to German queries following the update.
SISTRIX noted that while the data shows a correlation between the model change and citation movement, it does not definitively prove causation.
Source: Search Engine Journal
