Schema Markup's Impact on AI Citations: Study Reveals No Boost

Summary

A recent study has found that adding schema markup to web pages does not increase their likelihood of being cited by AI, debunking a long-held SEO belief. While AI-cited pages are more likely to have schema, a controlled experiment by Hrefs analyzing 1,885 pages that added JSON-LD schema between August 2025 and March 2026 found no significant citation boost across Google AI overviews, Google AI mode, or ChatGPT. In fact, AI overviews showed a small, statistically significant decline in citations. Researchers suggest that schema's presence on AI-cited pages is likely due to correlation rather than causation, as sites that implement schema often excel in other SEO factors like authoritative content and link building. The study also noted that major AI systems, during direct retrieval, primarily extract visible HTML content and ignore hidden structured data. Therefore, for pages already visible to AI, adding schema is unlikely to improve citation rates. The research advises focusing on relevance, authority, and user experience rather than schema for AI visibility.