The recent user growth charts from SimilarWeb reveal a fascinating narrative in the AI chatbot race. While both ChatGPT and Gemini show impressive growth trajectories from January to June 2025, the composition of their user bases tells distinctly different stories about their market positioning and future potential.
ChatGPT’s commanding lead remains evident, with the platform reaching approximately 410 million total users by June 2025, compared to Gemini’s 120 million. As of early 2025, ChatGPT has a significant market share at around 59.8% in the generative AI chatbot space, while Gemini holds 13.5%. According to recent court filings, Google estimated in March that ChatGPT had around 600 million MAUs, whereas Gemini only had 350 million MAUs.
However, what’s particularly striking is the proportion of new users each platform is attracting:
ChatGPT: Approximately 85 million new users (≈21% of total)
Gemini: Approximately 60 million new users (≈50% of total)
This dramatic difference in user composition suggests fundamentally different growth dynamics at play.
Why Gemini’s Growth Pattern Matters
1. The Google Ecosystem Advantage
Gemini’s higher proportion of new users can be attributed to Google’s strategic integration across its vast ecosystem. We’re starting to integrate Google Maps, Calendar, Tasks and Keep, with more Google ecosystem connections planned. This integration creates multiple touchpoints for user acquisition:
Seamless discovery through existing Google services
Lower barriers to entry – no separate app download required for many use cases
Natural workflow integration with Gmail, Docs, and other productivity tools
2. The “Free Premium” Strategy
Google has aggressively positioned Gemini’s advanced features in the free tier. The powerful Gemini 2.5 Pro AI model has been widely praised for its coding prowess and general capabilities. The advanced AI model is now available to free users as well. Additional free features include:
Deep Research AI agent – completely free for all users
Gemini Live with camera and screen sharing – now free on mobile
No limits on image generation (unlike ChatGPT’s restrictions)
3. Technical Superiority Claims
Recent benchmarks and user testimonials suggest Gemini is closing the capability gap: I hesitate even to say this (it causes me a significant amount of embarrassment and regret), but I used to spend $200 monthly on ChatGPT Pro. I guess maybe that’s the cost of doing business (I have found quite the niche being an AI writer, mainly focused on OpenAI products, so it’s my duty), but it was beginning to be too much. You may be surprised (or not) to find out that I canceled it yesterday. Why, you may ask? Well, it’s all because of a little model called Gemini 2.5 Pro.
ChatGPT’s Retention Advantage: The Incumbent’s Moat
Despite Gemini’s impressive new user acquisition, ChatGPT’s massive returning user base (approximately 325 million) demonstrates remarkable stickiness. This retention can be attributed to:
1. First-Mover Network Effects
Established workflows and habits
Extensive third-party integrations and custom GPTs
An impressive 92% of Fortune 500 companies report leveraging OpenAI’s products, including renowned brands such as Coca-Cola, Shopify, Snapchat, PwC, Quizlet, Canva, and Zapier.
Market Dynamics: Different Games, Different Rules
The contrasting growth patterns reflect fundamentally different market approaches:
Feature parity will increase as both platforms converge on capabilities
Medium-Term (2026-2027)
The “winner” may depend on use case segmentation rather than absolute dominance
Enterprise adoption will become the key battleground
Ecosystem lock-in effects will intensify as users invest in platform-specific workflows
Long-Term Considerations
The high proportion of new users for Gemini suggests significant untapped market potential remains. If Gemini can convert these new users into regular users while maintaining its acquisition pace, the market dynamics could shift dramatically.
However, ChatGPT’s retention superiority indicates that user satisfaction and habit formation remain its strongest assets. The question becomes: Can Gemini’s ecosystem advantages overcome ChatGPT’s product excellence?
The Bottom Line
The charts reveal not a simple horse race, but two different strategies playing out in real-time. ChatGPT has built a fortress of loyal users who return consistently, while Gemini is rapidly expanding the market by lowering barriers and leveraging Google’s reach.
For users, this competition is unequivocally positive. Both platforms are pushing each other to improve, resulting in:
The ultimate winner may not be the platform with the most users, but the one that best understands and serves the evolving needs of an AI-augmented workforce. Current trends suggest we’re heading toward a multi-platform future where ChatGPT and Gemini coexist, each dominating different use cases and user segments.
As Google is now in a much stronger position with its model offerings and feature set, compared to OpenAI. Yet ChatGPT’s enduring appeal proves that in the attention economy, being first and being best at core use cases creates a moat that’s difficult to cross – even for a tech giant with unlimited resources.
The race is far from over, and if these growth patterns hold, 2025 may be remembered as the year AI assistants became truly mainstream – not through the dominance of a single platform, but through the collective push of fierce competition.
Gennaro is the creator of FourWeekMBA, which reached about four million business people, comprising C-level executives, investors, analysts, product managers, and aspiring digital entrepreneurs in 2022 alone | He is also Director of Sales for a high-tech scaleup in the AI Industry | In 2012, Gennaro earned an International MBA with emphasis on Corporate Finance and Business Strategy.
