We track client visibility across eight AI platforms. One thing that surprises brands early on is how different the results are across each one. A hotel client of ours recently appeared in 60% of relevant ChatGPT prompts but only 15% on Gemini. A cultural institution showed up consistently on Perplexity but was invisible on ChatGPT entirely.

Same brand. Same content. Completely different outcomes depending on where someone asks the question. That's the landscape right now, and it's why monitoring a single platform gives you an incomplete picture of where you actually stand.

The big three and what makes them different

ChatGPT:

Remains the most-used AI platform, processing over 2.5 billion prompts per day as of early 2026. But its dominance is eroding. According to Similarweb data compiled by Clicky, ChatGPT's market share has contracted from 86% to roughly 64.5% over the past twelve months. What matters for brands is how it sources information. Ahrefs analyzed 9.6 million queries and found that Reddit accounts for nearly 30% of ChatGPT's U.S. citations, followed by Wikipedia at about 15%. Your own website is unlikely to be a primary source. ChatGPT builds its answer about your brand from what third parties say about you.

One detail that changes how you approach this: according to a Nectiv study of over 8,500 prompts, only about 31% trigger a live web search. The rest of the time, ChatGPT draws from training data. That means older, well-established content and brand signals carry real weight even when real-time search isn't happening.

Google Gemini:

The fastest-growing platform in the space. Gemini now holds 21.5% of the global AI chatbot market, up from roughly 5% just twelve months ago. The dedicated Gemini app has over 650 million monthly active users, and when you include AI Overviews in Google Search, that number reaches approximately 2 billion monthly users.

For brands, the critical difference is that Gemini has real-time access to Google's search index. That means traditional SEO signals like page speed, domain authority, structured data, and Google Business Profile accuracy matter more on Gemini than on any other AI platform. If your brand ranks well on Google, you have a head start. But it's not automatic. We've seen well-ranked sites that still don't appear in Gemini's AI answers because their content structure doesn't match what the model needs to generate a clean response.

Perplexity:

Occupies a different position entirely. It functions as an AI-first search engine rather than a general chatbot, with 45 million monthly active users and over 780 million queries processed per month. According to Profound's citation analysis, Reddit leads Perplexity's cited sources at 6.6%, with Wikipedia and YouTube following.

For premium brands, Perplexity's value is in its intent profile. Someone asking Perplexity for "best museum exhibitions in New York this spring" is probably making a plan, not browsing. And because Perplexity links directly to its sources, a citation there can actually drive traffic, something that rarely happens from ChatGPT or Gemini answers.

Why this fragmentation matters

The overlap between platforms is smaller than most people assume. Ahrefs found that only about 12% of URLs cited by ChatGPT rank in Google's traditional top 10 for the same queries. Similarly, only about 14% of URLs cited in Google's AI Mode overlap with its own traditional search results. Each platform draws from a different slice of the web and applies different criteria for what counts as trustworthy.

We see this in every client audit. A brand might have strong visibility on one platform and be completely absent from another. The reasons are almost always traceable to specific gaps: missing structured data that Gemini needs, lack of recent content that Perplexity favors, or thin third-party presence on the forums and review sites ChatGPT relies on.

The practical takeaway is straightforward. If you're only checking ChatGPT, you're seeing a fraction of the picture. A real visibility strategy requires monitoring across all major platforms and understanding which signals each one prioritizes. The fundamentals help everywhere: clear content structure, strong third-party citations, accurate entity information. But the weight each platform gives to those signals varies enough that platform-specific gaps are common and worth finding.

Check all of them. The results will be different, and the differences will tell you exactly where to focus.