For informational and comparison queries — the highest-value queries for brand discovery — AI search engines now handle 35–45% of all sessions. Google has lost nearly 15 percentage points of its informational query dominance since 2023.
Every year since 2004, Google Search has been the default entry point for the internet. Users with questions went to Google. Brands optimized for Google. Marketers measured Google rankings. That era is not over — but it is fracturing in ways that have profound implications for how brands invest in organic visibility.
This article aggregates data from Optymia AI's analysis of 500,000+ brand mention events across AI search platforms, third-party research from SimilarWeb and Semrush, and platform-disclosed user statistics to give the most accurate picture of the AI search landscape as of mid-2026.
Overall AI Search Market Share (Mid-2026)
The Query Type Breakdown: Where AI Search Has Already Won
The aggregate market share understates the urgency of the shift. When you break down sessions by query intent type, the picture for brands is more alarming:
| Query Type | Google Share | AI Engine Share | Brand Impact |
|---|---|---|---|
| Informational ('what is X') | 55% | 45% | ⚠️ GEO critical |
| Comparison ('X vs Y', 'best X') | 62% | 38% | ⚠️ GEO critical |
| How-To ('how to X') | 68% | 32% | ⚠️ GEO critical |
| Transactional ('buy X', 'X price') | 91% | 9% | ✅ Google SEO sufficient |
| Local ('X near me') | 96% | 4% | ✅ Google SEO sufficient |
| Research / Technical | 52% | 48% | ⚠️ GEO critical |
Platform-by-Platform Analysis
ChatGPT Search
OpenAI's ChatGPT Search launched in late 2024 and has become the dominant AI search platform by user count. With 600M monthly active users, it processes an estimated 2–3 billion search-intent queries per month. Its retrieval model combines live web search (via Bing partnership) with its training data, making it particularly strong at synthesizing comprehensive answers.
Key insight for brands: ChatGPT Search heavily weights pages with comprehensive JSON-LD schema, and its entity resolution strongly correlates with Wikidata entry completeness. Brands with a verified Wikidata item with 15+ properties see 3.2× higher citation rates compared to ungrounded brands.
Perplexity AI
Perplexity has emerged as the highest-citation-density AI search engine. Unlike ChatGPT which sometimes synthesizes from training data, Perplexity cites almost every substantive claim with a live source. This makes Perplexity optimization the highest-ROI GEO channel — being cited by Perplexity directly drives referral traffic in addition to brand authority.
Perplexity's growth rate of 300% YoY is the highest of any AI search platform. Its API is increasingly embedded in third-party tools and workflows, extending its retrieval surface beyond direct user queries.
Google Gemini (AI Overviews)
Google's response to the AI search shift has been AI Overviews — synthesized answer panels that appear above traditional blue link results. AI Overviews have dramatically reduced click-through rates on traditional organic results (contributing to the 22% CTR decline). Gemini as a standalone app is growing fastest in enterprise, driven by Google Workspace integration.
Critical insight: Optimizing for Gemini AI Overviews requires the same GEO signals as ChatGPT and Perplexity — entity authority, schema density, and structured content — making a unified GEO strategy effective across all platforms simultaneously.
What This Means for Your Brand Strategy
Your buyers are heavily using ChatGPT and Perplexity for vendor research. “Best tool for X” and comparison queries are 38–45% AI-handled. GEO is not optional — it's where your next 20% of pipeline is.
Your clients need GEO and most don't know it yet. The early mover advantage for agencies offering GEO services is an 18-month window before the market saturates. Start your GEO practice now.
Transactional queries are still Google-dominant (91%). But product research and comparison queries are shifting fast. Invest in review acquisition (G2, Trustpilot) and Q&A content to capture AI research traffic.
AI Overviews are cannibalizing informational traffic. AI citation (being the source Perplexity/ChatGPT cites) is the new version of ranking #1 on Google. Rebuild your content strategy around entity authority and Q&A formats.
Frequently Asked Questions
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Find Out Where Your Brand Stands in AI Search
Optymia AI tracks your brand's citation frequency across ChatGPT, Gemini, and Perplexity — giving you a live AI Visibility Score with actionable recommendations.