ChatGPT, Gemini, Perplexity & Claude compared
Why the systems answer differently
An AI answer depends on what it's built from: trained model knowledge, a live web search, or connected data sources. That's exactly where the providers differ — and therefore which brands they name and which sources they cite. The same question often yields noticeably different answers in ChatGPT, Gemini, Perplexity and Claude.
The systems in brief
- ChatGPT (OpenAI): the highest-reach system — 800 million weekly active users (Oct. 2025, Sam Altman), grown to around 900M–1B by 2026. Combines model knowledge with web search; expanding commerce and product features.
- Gemini (Google): tightly linked to Google Search, the Knowledge Graph and YouTube. Brands with a strong entity profile and YouTube presence have structural advantages here.
- Perplexity: built from the ground up as an "answer search engine" with visible citations; by third-party estimates around 45 million monthly users (2026). Citations are central to the user experience.
- Claude (Anthropic): answers strongly from model knowledge, with optional web search; widespread in professional and developer contexts.
What this means for you
Visibility isn't a single value; it varies by system. You can be prominently cited in Perplexity and missing in Gemini — say, because your entity profile or YouTube presence is weak. So: measure across several systems, understand the differences and work specifically where you have gaps. Check only ChatGPT and you see a fragment.
Sources
- OpenAI / Sam Altman (DevDay, Oct 6, 2025) — ChatGPT 800M WAU; grown to ~900M–1B by 2026.
- DemandSage (third-party estimate, 2026) — Perplexity ~45M MAU. (Estimate; Perplexity publishes no official figures.)
- Yext, "Knowledge Graph for AI Visibility" (2026); Knowhow_GEO_Landwehr.md — YouTube as a top source for Google LLMs.
In which AI systems are you named — and in which not? VISIBILIS measures your visibility across ChatGPT, Gemini, Perplexity and Google AI Overviews and shows the cited sources. Book a free demo
Key takeaways
- Each AI system draws on different data/sources and answers differently.
- Gemini is close to Google/Knowledge Graph/YouTube; Perplexity is citation-centric.
- ChatGPT has the largest reach (800M–1B WAU); Claude answers more from model knowledge.
- Measure across several systems — visibility in one isn't visibility everywhere.
Frequently asked questions
Is being visible only in ChatGPT enough?
No. ChatGPT, Gemini, Perplexity and Claude answer differently and draw on different sources; your audience is spread across them. Visibility in one system says little about the others.
Why am I named less often in Gemini than in Perplexity?
Often because of the entity profile and YouTube presence that Gemini (Google) weights heavily, while Perplexity cites more broadly from live web search. It's worth measuring both separately.
Do the differences between the AI systems change over time?
Constantly. Providers update models and source logic continuously — another reason to measure on an ongoing basis and across several systems rather than once.