Reasoning
As of mid-2026, AI-generated content has proliferated rapidly across the web following widespread adoption of generative AI tools (ChatGPT, Claude, Gemini, etc.) since 2022-2023. Google and other search engines have already begun reporting significant increases in AI-generated indexed content—estimates from 2024-2025 suggested 15-25% of new indexed pages contained substantial AI-generated material. The trajectory from ~20% currently to >30% by 2028 (18 months away) represents a ~50% increase, which is plausible given: (1) continued cost advantages of AI generation, (2) minimal enforcement of disclosure requirements, (3) SEO incentives for bulk content generation, and (4) declining quality thresholds as competition intensifies. However, this assumes "primarily AI-generated" (>50% AI content) rather than merely "containing AI content," which is a higher bar. Counterbalancing factors include potential platform policy tightening, algorithmic de-ranking of obvious AI content, and advertiser pressure against low-quality AI farms.Key uncertainty
Whether Google will officially report such metrics publicly at all—the company may choose not to quantify AI-generated content prevalence due to reputational and advertiser concerns, making verification of this specific claim impossible regardless of actual prevalence rates.