Introduction to Google’s AI Features
Google has been working on improving its AI features, including AI Mode and AI Overviews. These features are designed to provide users with accurate and helpful information. Recently, Ahrefs conducted a study to compare the responses of AI Mode and AI Overviews for the same queries. The study analyzed data from September 2025 and found some interesting results.
What the Study Found
The study compared 730,000 query pairs for content similarity and 540,000 query pairs for citation and URL analysis. The results showed that AI Mode and AI Overviews cited the same URLs only 13% of the time. When comparing only the top three citations in each response, the overlap increased to 16%. The language used in the responses also varied, with only 16% overlap in unique words. However, the study found strong semantic alignment, with an average semantic similarity score of 86%. This means that 9 out of 10 times, AI Mode and AI Overview agreed on what to say, but they said it differently and cited different sources.
Different Source Preferences
The study found that AI Mode and AI Overviews have different source preferences. For example, Wikipedia appears in 28.9% of AI Mode citations, compared to 18.1% in AI Overviews. AI Mode also cited Quora 3.5x more often and cited health sites at roughly double the rate of AI Overviews. On the other hand, AI Overviews leaned more heavily on video content, with YouTube being the most frequently cited source. AI Overviews also cited videos and core pages nearly twice as often as AI Mode.
Entity and Brand Mentions
The study found that AI Mode responses were about four times longer than AI Overviews on average and included more entities. AI Mode averaged 3.3 entity mentions per response, compared to 1.3 for AI Overviews. Approximately 61% of the time, AI Mode included all entities mentioned in the AI Overview response and then added additional entities. Many responses didn’t include brands or entities, with 59.41% of AI Overview responses and 34.66% of AI Mode responses containing no mentions of persons or brands.
Citation Gaps
The study found that AI Mode was more likely to include citations than AI Overviews. Only 3% of AI Mode responses lacked sources, compared to 11% of AI Overviews. Missing citations typically occur in cases such as calculations, sensitive queries, help center redirects, or unsupported languages.
Why This Matters
This study suggests that AI Mode and AI Overviews can differ in the sources they credit, even when they reach similar conclusions for the same query. This can affect how you interpret "visibility" across experiences. A citation in AI Overviews does not necessarily imply you will be cited in AI Mode for the same query, and AI Mode’s longer responses may include additional entities and competitors compared to the shorter AI Overview format.
Looking Ahead
Ahrefs notes that this analysis compares single generations of AI Mode and AI Overview responses. In related research, Ahrefs reported that 45.5% of AI Overview citations change when AI Overviews update, suggesting that overlap can appear different across repeated runs. Even with that caveat, the low overlap observed in this dataset indicates that AI Mode and AI Overviews frequently select different URLs as supporting sources for the same query.
Conclusion
In conclusion, the study by Ahrefs provides valuable insights into the differences between Google’s AI Mode and AI Overviews. The findings suggest that while both features can provide similar information, they often cite different sources and use different language. This has implications for how we interpret "visibility" across experiences and highlights the importance of considering multiple sources when evaluating information. As Google continues to develop and improve its AI features, it will be interesting to see how these differences evolve and what implications they may have for users and content creators.