ChatGPT Citations Shift Post-GPT-5.5: SISTRIX Data Reveals

Citation patterns in ChatGPT responses changed significantly after the implementation of GPT-5.5, according to a SISTRIX analysis. This change is based on 3.8 million German-language ChatGPT responses. What's interesting is that the analysis tracked 38 daily samples of 100,000 responses. Before the change, citation patterns varied by 1-2% daily. But during the model identifier change on May 22nd and 23rd, this jumped to 47%. The average number of cited sources per response also dropped from 30.9 to 28.4. Reddit saw the largest gain, adding 7,007 citations per 10,000 responses, a 59% increase. German mainstream publishers like Welt.de, faz.net, and bild.de also saw significant increases, as did German streaming and sports platforms. Specialized tools like Mapbox.com and Openstreetmap.org gained as well. On the other hand, international aggregator platforms like Indeed, Tripadvisor, and Expedia saw steep declines, with drops between 47% and 60%. Global tech platforms such as YouTube, Wikipedia, and Google.com also lost ground. The bottom line is that this data suggests ChatGPT's citation behavior is evolving with each new model, which can impact the information users receive.