Which search index does each AI assistant use?

Different assistants read the web through different indexes, and knowing the map tells you where to be present. Microsoft Copilot and much of ChatGPT browsing lean on the Bing index (alongside OpenAI crawling its own), so Bing coverage matters more than most businesses realize. Google powers Gemini, AI Overviews and AI Mode, so Google indexing and Search Console remain central. Perplexity blends its own index with mainstream web results, Claude reads the live web through its own retrieval, and Grok leans on X plus general web results. The practical takeaway is simple: no single index covers them all, so a business that wants to be findable across them needs to be cleanly crawlable and indexed in both Bing and Google at minimum. That means allowing the relevant crawlers, submitting your sitemap to Google Search Console, and using IndexNow to push updates to Bing — plus the usual entity and structured-data fundamentals so that whichever index an assistant reads, it finds a clear, consistent picture of you.

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