How often does ChatGPT search the web before answering?

ChatGPT triggered a web search for 87.8% of answers in July. That puts it neck and neck with Perplexity at 88.7% and just behind Google AI Overviews at 92%. Across these three engines, most AI answers now pull from the live web.

The numbers come from 9,320 responses tracked across four AI engines over the month. Google AI Overviews hit 92% across 2,497 responses. Perplexity followed at 88.7% from 2,471 responses. ChatGPT landed at 87.8% across 2,271 responses.

The three engines sit within about four percentage points of each other. That narrow spread points to a shared default: search the web unless there is a strong reason not to. The default across the AI landscape is search-on.

Google AI Mode never searched the web. Across 2,081 responses, not one triggered a search. Zero percent. That is not noise — 2,081 responses is a meaningful sample. Google AI Mode looks like a fundamentally different product from Google AI Overviews, relying entirely on the model's internal knowledge.

That split inside Google is the most interesting signal in the data. Google AI Overviews searches the web 92% of the time. Google AI Mode never does. Same company, two products that behave like opposites — one retrieval-heavy, one retrieval-free.

For marketers, this changes where effort goes. Google AI Overviews and Perplexity pull from the web for nearly every answer. ChatGPT does the same 87.8% of the time. Google AI Mode never does. A one-size-fits-all AI visibility strategy misses the biggest split in the market.

The 0% figure for Google AI Mode raises a question the data cannot answer yet: what knowledge base does it draw from? If it never triggers a detectable web search, its answers come from training data, fine-tuning, or some internal retrieval system that does not register as a search. Either way, conventional web optimization will not reach it.

Web search is not fading. Three of the four engines tracked search the web for almost every answer. Google AI Mode, at 0%, is the odd one out — and a reminder that not all AI engines play by the same retrieval rules.