--- title: "How ChatGPT, Claude, Perplexity and Google AI find their sources" slug: how-ai-search-finds-sources cluster: ai-search type: spoke description: "A plain-English look at how the main AI assistants find web sources about a business, and what that means for owners who want accurate answers." answer: "ChatGPT, Claude and Perplexity each run their own search crawler and index, and fetch pages live when a user asks. Google's AI Overviews and AI Mode draw on Google Search's normal index. All of them retrieve candidate pages, choose a few readable, relevant sources and combine them into one answer. Being crawlable and clear is the precondition. Nothing guarantees a citation." published: 2026-11-05 updated: 2026-11-05 author: "About This Business editorial team" takeaways: - "Each assistant has its own crawler and index, and also fetches pages live for some questions." - "Google's AI features use Google Search's index, with no extra requirements." - "Ranking well in one system doesn't guarantee being picked by another." - "Clear, specific, current passages are what assistants find easiest to use." imagePrompt: "Several old brass telescopes and a magnifying glass arranged on a wooden map table, each pointing in a different direction across scattered blank papers, warm golden light through a window, a sense of searching many places at once, no legible text" imageAlt: "Brass telescopes and a magnifying glass on a wooden map table pointing in different directions" faq: - q: "Does ChatGPT use Google's results?" a: "OpenAI documents its own search crawler, OAI-SearchBot, for ChatGPT search, and ChatGPT search also works with outside search providers. Don't assume a high Google ranking means ChatGPT will use your page, or the reverse." - q: "Why do different assistants give different answers about my business?" a: "They use different indexes, run different queries and choose different sources. If your facts are inconsistent across the web, each assistant may land on a different version." - q: "Do assistants prefer recent content?" a: "For many questions, current information matters, and dated content makes it clear what's current. Visible dates help both readers and machines judge freshness." sources: - title: "OpenAI — Overview of OpenAI crawlers" url: "https://platform.openai.com/docs/bots" - title: "Anthropic — Does Anthropic crawl data from the web?" url: "https://support.claude.com/en/articles/8896518" - title: "Perplexity — Perplexity crawlers" url: "https://docs.perplexity.ai/docs/resources/perplexity-crawlers" - title: "Google Search Central — AI features and your website" url: "https://developers.google.com/search/docs/appearance/ai-features" --- ## What are the basic steps every AI assistant follows? **Interpret the question, retrieve candidate pages, choose a few sources, and write a combined answer.** The details differ by assistant, but the loop is the same. This article looks at where each assistant gets its candidate pages. For the bigger picture, see [How AI assistants decide what to say about your business](/knowledge/ai-search). ## Where does ChatGPT get its sources? **From OpenAI's own search crawler, OAI-SearchBot, from live fetches when a user asks, and from outside search providers.** OpenAI documents separate crawlers for separate jobs: OAI-SearchBot surfaces websites in ChatGPT's search features, ChatGPT-User fetches pages for specific user requests, and GPTBot collects training data. OpenAI states that sites opting out of OAI-SearchBot won't be shown in ChatGPT search answers, though they can still appear as navigational links. ## Where does Claude get its sources? **From Anthropic's search crawler, Claude-SearchBot, and from live fetches by Claude-User when a user's question needs a page.** ClaudeBot is separate and is used for model training. Anthropic says disabling Claude-SearchBot may reduce your visibility and accuracy in Claude's search results, and disabling Claude-User stops Claude retrieving your pages for user questions. ## Where does Perplexity get its sources? **From its own index, built by PerplexityBot, plus live fetches by Perplexity-User.** Perplexity says PerplexityBot surfaces and links websites in its search results and isn't used to train foundation models. It recommends allowing PerplexityBot if you want to appear. ## Where do Google's AI Overviews and AI Mode get their sources? **From Google Search's normal index, the same one used for regular results.** Google says there are no additional requirements to appear in AI Overviews or AI Mode: a page must be indexed and eligible to show with a snippet. Ordinary SEO foundations apply, such as crawlable pages, internal links, important content in text and structured data that matches the page. ## How do the assistants compare? | | Own crawler/index | Live fetch for users | Extra requirements | |---|---|---|---| | ChatGPT | OAI-SearchBot | ChatGPT-User | Allow OAI-SearchBot | | Claude | Claude-SearchBot | Claude-User | Allow Claude-SearchBot | | Perplexity | PerplexityBot | Perplexity-User | Allow PerplexityBot | | Google AI features | Google Search index | — | None beyond normal Search eligibility | ## What does this mean for a business owner? **Make sure every assistant can reach you, then make your facts the clearest and most consistent version available.** 1. **Allow the search crawlers.** See [AI crawlers and robots.txt](/knowledge/ai-search/ai-crawlers-and-robots-txt). 2. **Put key facts in plain HTML text**, not only in images, PDFs or scripts. 3. **Write answer-first passages** that make sense on their own. 4. **Keep facts consistent everywhere.** See [When AI gets your business wrong](/knowledge/ai-search/when-ai-gets-your-business-wrong). 5. **Date your facts** so assistants can tell current from old. See [Why every business fact needs a source and an "as of" date](/knowledge/business-dna/why-facts-need-sources-and-dates). --- Part of **[How AI assistants decide what to say about your business](/knowledge/ai-search)**.