The AI Visibility Index 2026 examines how ChatGPT, Gemini, Claude, and Perplexity represent 122 brands across 9 sectors. The report analyzes 7,580 unique prompts and 4.169 million cross-model prompt runs to identify the gap between brand recognition and AI discovery. It explores AI visibility, brand inclusion, model volatility, discovery gaps, content readiness, citations, and sector-level performance. The research provides practical insights into measuring and improving brand visibility across AI search and generative AI platforms.