Who Uses Which AI Assistant in May 2026
The AI assistant market in mid-2026 is roughly the size of Facebook's English-speaking user base, with consolidation happening at the top while the long tail expands. This page consolidates the most-cited monthly active user (MAU), weekly active user (WAU), and mobile-app MAU figures for the eight major AI assistants as of May 2026, drawn from vendor disclosures, earnings calls, third-party measurement, and DataReportal's Digital 2026 report.
Monthly Active Users by Platform (May 2026)
| Platform | Vendor | MAU (All Surfaces) | Notable Detail |
|---|---|---|---|
| Meta AI | Meta | ~1 billion | Includes WhatsApp, Instagram, Messenger, Ray-Ban Meta surfaces |
| ChatGPT | OpenAI | ~400 million | 900M weekly active users (Feb 2026) |
| Microsoft Copilot | Microsoft | 218-420 million* | Wide range across sources; 15M paid M365 seats |
| Gemini | ~400 million | Includes consumer + Workspace surfaces | |
| DeepSeek | DeepSeek | ~97 million | Primarily Chinese-language user base |
| Claude (claude.ai) | Anthropic | ~30 million | Growing rapidly; enterprise-skewed |
| Grok | xAI | 20-35 million | Distributed via X (Twitter) integration |
| Perplexity | Perplexity | ~22 million | Search-focused; high engagement per session |
*Microsoft Copilot figures vary between 218M and 420M across sources because vendors and analysts include different surface combinations (Windows + Edge + M365 + Bing + mobile). The 420M figure represents the broadest surface count; 218M is a narrower (Windows + app + web) count.
Mobile App MAU (Google Play + iOS Combined)
| App | Mobile MAU |
|---|---|
| ChatGPT | ~557 million |
| Gemini | ~70 million |
| Grok | ~39 million |
| Perplexity | ~39 million |
ChatGPT's mobile-app MAU exceeds Gemini's by roughly 8x, despite the two having comparable total MAU. The gap reflects ChatGPT's standalone-app distribution versus Gemini's reliance on Google's Workspace and Search integrations.
US Market Share of AI Chatbot Visits (May 2026)
| Platform | US Share |
|---|---|
| ChatGPT | 59.5% |
| Microsoft Copilot | 14.0% |
| Gemini | 13.4% |
| Perplexity | 6.2% |
| Claude | 3.2% |
| Other (Grok, DeepSeek, You.com, Meta AI web, etc.) | ~3.7% |
Enterprise Adoption (Microsoft Copilot Specifically)
| Metric | Value |
|---|---|
| Microsoft 365 Copilot paid seats (Q1 2026) | 15 million |
| Active workplace users | 33 million |
| Workplace conversion rate (paid seats utilised) | ~36% |
| Daily interactions per active enterprise user | 11.3 |
| Enterprise users reporting daily Copilot usage | 67% |
| Largest disclosed enterprise rollout (Accenture) | 743,000 seats, 89% monthly active |
Six Things the Numbers Tell You
- Meta AI's ~1 billion MAU is the largest of any AI assistant. The number is distributed across WhatsApp, Instagram, Messenger, and Ray-Ban Meta and is partly automatic (users opted in via prompts in the host app), so engagement-per-user is lower than ChatGPT. By active-deliberate use, ChatGPT's 400M MAU is larger.
- ChatGPT's 900M WAU is roughly half the population of the global internet. 5.5 billion global internet users in 2026 means ChatGPT touches approximately 16 percent of them in any given week. The penetration is highest in the US, where the platform holds 59.5 percent of AI chatbot visits.
- The Gemini and Copilot gap with ChatGPT is narrower by surface count than by deliberate-use. Both Gemini (400M) and Copilot (high end of 420M) match ChatGPT on total MAU when all surfaces are counted (Workspace, Edge, M365). But ChatGPT's standalone-app footprint is 8x Gemini's mobile-app MAU, suggesting that deliberate "open the AI app" use still concentrates on ChatGPT.
- Microsoft Copilot enterprise conversion is approximately 36 percent. 15M paid M365 seats versus 33M actual workplace users translates to roughly one in three paid seats actively used. The gap is the structural reason Microsoft has prioritised in-product Copilot prompts and embedded auto-summary features in Outlook, Teams, and Excel.
- Claude punches above its MAU weight on engagement. 30M MAU is a fraction of ChatGPT's 400M, but Anthropic's reported API call volume (25B monthly in Q2 2025) per user is dramatically higher because Claude skews enterprise and developer. The user-base composition matters more than the absolute MAU number for B2B brand-visibility programmes.
- The total deliberate-use AI assistant audience exceeds 1 billion as of 2026. DataReportal's Digital 2026 report places the combined deliberate-user audience above the one-billion threshold for the first time. Penetration is now comparable to mobile messaging at the population level in developed markets.
What This Means for AI Visibility
Brand-visibility programmes that track only ChatGPT capture roughly 60 percent of the US AI chatbot surface but miss the remaining 40 percent split across Copilot, Gemini, Perplexity, Claude, and the long tail. The cost-vs-coverage math is uneven: Claude and Perplexity have low MAU but high engagement-per-user in commercial buyer demographics, which makes them disproportionately valuable for B2B and high-AOV B2C brands. For consumer brands, ChatGPT + Gemini + Copilot covers the bulk of attention; for enterprise brands, add Claude and Perplexity. Meta AI's 1B MAU is largely consumer-passive surface area where deliberate brand-recommendation queries are less common, so prioritisation should reflect deliberate-query share rather than raw MAU.
Methodology
MAU and WAU figures collected on May 14, 2026 from vendor announcements, earnings disclosures, DataReportal's Digital 2026 report, Business of Apps Microsoft Copilot statistics, First Page Sage US chatbot share data, and third-party mobile-app measurement firms. MAU definitions vary by vendor (logged-in vs anonymous, all surfaces vs primary surface). Where source figures conflict materially, we report a range with the methodology note. Refreshed quarterly.
How Presenc AI Helps
Presenc AI tracks brand-mention rates across the eight platforms ranked above. The MAU table tells you which platforms have the audience; Presenc AI tells you whether your brand surfaces inside the recommendations each platform makes to that audience. For brand-visibility budget allocation, the right composite metric is "MAU × brand-mention rate × deliberate-query rate," and the MAU column above is the input to the first of those three multipliers.