The AI Search Duopoly: ChatGPT + Gemini Control 86% of Market Share
Similarweb data shows ChatGPT and Gemini now control 86.2% of AI search. If you're not optimizing for both, you're invisible to most AI users.
New market data from Similarweb reveals a stark consolidation in AI search: ChatGPT and Google Gemini together now control 86.2% of the AI chatbot market, with ChatGPT holding 68% and Gemini surging to 18.2%. This duopoly is forming faster than industry observers predicted, leaving third-tier competitors fighting for scraps.
The implications for brands tracking AI visibility are profound. If you're not optimizing for ChatGPT and Gemini, you're essentially invisible in AI search results.
The Data: Market Share Consolidation
According to Similarweb's January 2026 analysis:
- ChatGPT: 68.2% market share (down from 2025 highs but still dominant)
- Google Gemini: 18% market share (surging from single digits in 2025)
- Combined duopoly: 86.2% total market control
- Everyone else: Fighting for the remaining 13.8%
Notably, Perplexity's market share has declined from 2.4% three months ago to just 2.0% currently—now trailing behind Grok for the first time in months. This decline is particularly significant given Perplexity's positioning as a "search-focused AI service." If specialized search tools can't maintain share, what does that mean for niche players?
Why the Duopoly Is Forming So Fast
Three structural factors are accelerating consolidation:
1. Distribution Advantage
ChatGPT has massive consumer adoption and brand recognition. Gemini benefits from Google's search dominance and Android integration. Both platforms have distribution advantages that third-tier competitors simply cannot match.
When Gemini is baked into every Android device and Google Search, and ChatGPT is the default AI assistant for millions of users, smaller players face an insurmountable distribution gap.
2. Infrastructure Costs
Running AI search engines at scale requires massive infrastructure investment. OpenAI and Google have the capital and existing infrastructure to operate at scale. Smaller players like Perplexity face unit economics challenges that make sustainable growth nearly impossible.
The recent Microsoft-Perplexity deal signals this reality: even well-funded AI search startups need partnerships with tech giants to survive infrastructure costs.
3. Training Data Moats
ChatGPT and Gemini benefit from years of user interactions, creating training data moats that improve answer quality over time. The more users they have, the better their models become, creating a reinforcing cycle that smaller competitors can't replicate.
When ChatGPT processes hundreds of millions of queries weekly, it learns patterns and improves answers faster than competitors processing a fraction of that volume. This creates a quality gap that only widens over time.
What This Means for Brand AI Visibility
For brands optimizing for AI search visibility, the duopoly creates both challenges and opportunities:
Opportunity: Simplified Targeting
With 86.2% of the market controlled by two players, brands can focus optimization efforts on ChatGPT and Gemini rather than spreading resources across multiple platforms. This concentration actually simplifies AI visibility strategy—if you dominate in ChatGPT and Gemini responses, you dominate AI search.
Challenge: Higher Stakes
When two platforms control the market, being absent from their responses means you're essentially invisible in AI search. The stakes are higher: you must optimize for these platforms or accept invisibility.
Earned Media Becomes More Critical
Both ChatGPT and Gemini prioritize earned media citations from authoritative sources. Research shows 85-95% of AI citations come from earned media (Forbes, TechCrunch, WSJ, etc.) rather than brand-owned content. In a duopoly, securing earned media placements that both platforms trust becomes even more critical for AI visibility.
The Perplexity Problem
Perplexity's decline from 2.4% to 2.0% market share—and falling behind Grok—signals a broader problem for specialized AI search tools. If a search-focused AI service can't maintain share against general-purpose chatbots, what's the value proposition?
The answer may be that "AI search" as a category is being subsumed by general-purpose AI assistants. Users don't want specialized search tools—they want conversational AI that can both answer questions and perform tasks. ChatGPT and Gemini win because they do both.
For brands, this means optimizing for general-purpose AI assistants rather than specialized search tools. The future of AI visibility isn't about ranking in AI search engines—it's about being cited by AI assistants when they answer questions.
What Brands Should Do Now
Here's how to adapt to the AI search duopoly:
1. Focus on ChatGPT and Gemini
Prioritize optimization for the two platforms that control 86% of the market. Test queries in both platforms regularly. Track which queries trigger brand mentions and which don't. Optimize earned media strategy to target publications that ChatGPT and Gemini cite most frequently.
2. Double Down on Earned Media
Secure placements in Tier 1 publications that both platforms trust: Forbes, TechCrunch, The Wall Street Journal, and industry-leading outlets. Earned media is the foundation of AI visibility—85-95% of AI citations come from earned media sources.
3. Monitor Consolidation Trends
Track market share shifts monthly. If the duopoly strengthens further, adjust strategy accordingly. If new players emerge, evaluate whether they're worth optimization effort based on actual market share, not hype.
4. Optimize for General-Purpose AI, Not "Search"
Position your brand for conversational AI assistance, not just search results. The future of AI visibility is being cited when AI assistants answer questions, not ranking in specialized search tools.
The Future: Will the Duopoly Hold?
Three scenarios for AI search market evolution:
Scenario 1: Duopoly Strengthens - ChatGPT and Gemini continue consolidating market share, reaching 90%+ combined control. Third-tier players either get acquired or fade into irrelevance. This is the most likely scenario based on current trends. Scenario 2: Third Player Emerges - A new competitor (Meta's AI, Anthropic's Claude, or another player) achieves meaningful distribution and captures 10-15% market share, creating a triopoly. This requires solving the distribution and infrastructure challenges that Perplexity couldn't overcome. Scenario 3: Niche Specialization - Third-tier players survive by focusing on specific verticals or use cases rather than competing head-to-head with general-purpose AI. This seems unlikely given the data—even search-focused Perplexity is losing share to general-purpose tools.
The data suggests Scenario 1 is most likely. The duopoly will strengthen, and brands must optimize accordingly.
Conclusion
The AI search duopoly is forming faster than expected. ChatGPT and Gemini control 86.2% of the market, and that share is growing. For brands optimizing for AI visibility, this consolidation simplifies targeting but raises stakes: if you're not optimized for these two platforms, you're essentially invisible in AI search.
The key to AI visibility in a duopoly? Earned media placements in publications that both platforms trust. 85-95% of AI citations come from earned media, making Tier 1 placements more valuable than ever.
AuthorityTech optimizes all earned media placements for AI search results, ensuring maximum visibility in ChatGPT and Gemini. We don't chase vanity metrics—we focus on what actually matters: AI visibility, earned media placements, and real results.
The duopoly is here. Optimize for it or accept invisibility.
Sources & Further Reading