Ahrefs shared an AI Search Benchmark Report (PDF) with findings from 13 individual studies they conducted in Q4 2025 and Q1 2026. Highlights:

• AI Overviews appear for 21% of all keywords, much more often on long, informational queries.
• Single-word queries trigger AIOs 9.5% of the time; queries with 7+ words hit 46.4%.
• AI Mode & AI Overviews agree in substance, but cite different sources: Only 13.7% URL overlap, yet they reach the same conclusion 86% of the time.
• 28% of ChatGPT’s top-cited pages have zero organic keywords. You still have a chance of visibility in ChatGPT even without traditional ranking performance.
• Only 37.9% of cited URLs in AIO rank in the top 10, down from about 76% in Ahrefs’ earlier study.
• Brand mentions don’t reliably earn links: When Ahrefs is mentioned in AI responses, it gets linked only 28% of the time overall.
• YouTube mentions had the strongest correlation with AI brand visibility across ChatGPT, AI Mode, and AI Overviews.
• AIO citations have near-zero correlation with content length; 53.4% of cited pages were under 1,000 words.
• For top-of-funnel ChatGPT queries, “Best X” blog lists made up 43.8% of source URLs.
• AIO are global & uneven: Indonesia leads with 37.2% AIO coverage (U.S. rate is 20.5%)
• Position #1 results saw a 58% CTR reduction when AIOs were present; position #10 lost 19.4%.
• ChatGPT has about 12% of Google’s search volume, but Google sends 190x more traffic to websites.
• Most AI tools repeated fake brand claims planted online; ChatGPT performed better, Claude avoided hallucinating but missed the official site.
• AIOs are unstable in wording, stable in meaning: They changed between observations 70% of the time, but their core message stayed highly consistent.