The US search landscape leads with a small number of portals, and we weight our rails accordingly. As of June 2026, StatCounter share puts Google at 86.67% and Bing at 8.73%, with Yahoo Search at 2.55% and DuckDuckGo at 1.53% — so our US search rail leads with Google Search and Bing Search and keeps the smaller portals as secondary diagnostics under the en-US contract.
US search
Google Search and Bing Search lead; Yahoo Search and DuckDuckGo as diagnostics
Google AI Overviews and organic results are read on Google Search; Bing Search carries its own AI answer surface. Yahoo Search and DuckDuckGo stay visible as secondary portal diagnostics rather than headline rails.
US AI answers
Named AI-answer interfaces
ChatGPT, Perplexity, Claude and Gemini are recorded by exact interface, target, receipt and evidence namespace. Location-capable direct API rails and approved regional observation are logged by exact interface, target, receipt and evidence namespace — official API, consumer chat UI and clean-session tests each on their own rail.
Provenance
Exact interface labels
Every run records interface, model, location, language, device where applicable, cache policy, capture time, run index and source receipt — so the same conditions can be measured again.
Every observation keeps its exact interface label and a content-addressed receipt. Official API, consumer chat UI, clean-session tests and causal evaluation each use a separate evidence rail and denominator.