AI indexing is the process by which an AI system crawls, stores, and retrieves your site's content so it can cite you in an answer. Each major AI platform runs its own separate index, built by its own crawlers, disconnected from Google's search index and from every other platform's index. Ranking on Google says nothing about whether ChatGPT, Claude, or Perplexity can find you.
How AI Indexing Works
The process runs in three stages. A crawler fetches the page, the platform processes the content, and the result lands in a retrievable store. The model pulls from that store when answering a question. That store is the AI-era equivalent of a search engine's index, built and maintained by the platform itself.
Each platform runs this process independently. OpenAI, Anthropic, Perplexity, and Google each maintain their own crawl and retrieval systems, and none of them share data with each other. A page can sit in one platform's index and be completely absent from another's. That holds even if both platforms crawled the same domain on the same day.
How AI Indexing Differs From Google Indexing
Google's AI features run on the Search index, not a separate one. AI Overviews and AI Mode pull from the same index that powers regular results. A page just needs to be indexed and eligible to appear in Search already. According to Google Search Central, there are no additional requirements to appear in AI Overviews or AI Mode beyond standard indexing and search eligibility.
ChatGPT, Claude, and Perplexity work the opposite way. ChatGPT combines what OAI-SearchBot collects with results from third-party search providers, including Bing. Claude and Perplexity run their own retrieval layers the same way, independent of Google. Strong Google rankings do not transfer, because none of this runs on Google's index.
The Crawlers Building Each AI Index
Most AI platforms run two to four separate bots, and each one serves a different purpose. Confusing them is the most common reason a brand blocks the wrong one and disappears from citations without realizing why.
OpenAI runs four bots, according to OpenAI's developer documentation. GPTBot crawls for model training. OAI-SearchBot builds the index behind ChatGPT's search feature, and blocking it removes you from ChatGPT search answers. ChatGPT-User fires only when a live user's question sends the model to fetch a specific page in real time. OpenAI states it is not used for crawling the web in an automatic fashion. OAI-AdsBot checks the landing pages of ads submitted to ChatGPT. The data it collects is not used to train foundation models.
Anthropic runs three bots along similar lines, according to Anthropic's crawler documentation. ClaudeBot collects training data. Claude-SearchBot "navigates the web to improve search result quality," building the index Claude cites from. Claude-User handles live, in-conversation fetches when a person asks Claude a direct question.
Perplexity uses two, according to Perplexity's documentation. PerplexityBot crawls to build the index behind cited answers. Per Perplexity, it is not used to crawl content for AI foundation models. Perplexity-User triggers only on a live user query and generally ignores robots.txt, since it behaves like a browser request rather than an automated crawl.
Google uses no separate crawler for this. Google-Extended is a robots.txt token with no user agent of its own, according to Google Search Central. It controls whether Google may use crawled content to train Gemini models and to ground answers in Gemini Apps and Vertex AI. It has no bearing on AI Overviews or AI Mode, and Google states it does not affect inclusion in Search.
How to Check Whether AI Has Indexed Your Site
Server logs are the most direct check, because standard analytics tools cannot see this traffic. Google Analytics and other JavaScript-based trackers only fire after a browser executes a script. OpenAI's, Anthropic's, and Perplexity's crawlers do not execute JavaScript, according to Vercel's analysis of AI crawler traffic. Every one of these visits is invisible to a client-side dashboard as a result.
Filter your raw server logs for the user-agent strings above, then confirm the request came from the real crawler rather than a spoofed one. OpenAI, Anthropic, and Perplexity all publish IP range files for exactly this reason. A request claiming to be GPTBot from an IP outside OpenAI's published range is not GPTBot, and blocking it costs you nothing.
Google Search Console gives you a rough second signal, though it measures Google rather than the AI platforms. Filtering for long conversational queries surfaces the phrasing people use with an assistant:
- Open the Search Results report.
- Select Add Filter, then Query.
- Change the match type to Custom Regex.
- Enter `([^" "]*\s){7,}?` to return queries of seven words or more.
Treat that list as directional. It catches long human searches alongside assistant-style ones, and it says nothing about whether ChatGPT or Perplexity holds your pages.
This matters more each quarter. AI search visits rose from 15.6 billion to 27.4 billion between the first quarters of 2025 and 2026, according to Wix's AI Search Lab. A brand invisible to these crawlers is missing a growing share of how people find products. Checking logs across four platforms by hand does not scale, which is what OmniGro's AI Citation Tracking is built to automate. If you want a quick manual check first, see how to know if AI is recommending your brand.
What Blocks AI Indexing
Three issues keep most pages out of an AI index: robots.txt errors, JavaScript-only rendering, and content too thin or duplicate to be worth retrieving.
Robots.txt errors. Blocking GPTBot opts you out of training and nothing more, since OpenAI treats each bot's setting independently. Blocking OAI-SearchBot, though, removes you from ChatGPT search answers entirely. Check each directive against the bot's actual purpose before disallowing it.
JavaScript-rendered content. AI crawlers read the raw HTML response, not the page a browser renders after scripts run. Content injected client-side is invisible to them, the same blind spot that hides content in accordions and tabs from AI extractors. Single-page apps are the worst case, and why client-side rendering makes a site invisible to AI crawlers covers the diagnosis and the fix.
Thin or duplicate content. Pages with little unique text, or that duplicate another page on the site, are less likely to be retrieved and cited, even once indexed.
FAQs
Does ranking well on Google mean AI will index me too?
No. Google Search and Google's AI features share one index, but ChatGPT, Claude, and Perplexity run entirely separate crawlers and indexes. A page can rank on page one of Google and be completely unindexed by every AI platform.
How is AI indexing different from being cited by ChatGPT?
Indexing comes first. A page has to be in an AI platform's index before the model can retrieve and cite it. Being indexed does not guarantee a citation, but it is a requirement for one.
Can I check AI indexing without server access?
Partly. Bing Webmaster Tools' AI Performance report shows citations on Microsoft-powered surfaces, and CDN logs can show crawler hits without full server access. For coverage across ChatGPT, Claude, and Perplexity, though, log-level data or a tracking service is what actually works. Asking an AI model directly whether it has "seen" your site is not a valid test. Models answer from training data, not a live index lookup.
Does blocking GPTBot hurt my AI visibility?
Not by itself. GPTBot handles training only. Blocking it opts your content out of future model training without affecting whether OAI-SearchBot can still index your pages or ChatGPT-User can fetch them live.
How often do AI crawlers re-index a site?
There's no published fixed schedule, and it varies by platform and by how often a page changes. Pages that update frequently and are linked to elsewhere tend to get re-crawled more often than static pages.
Conclusion
AI indexing determines whether your brand can be found at all before it determines whether it gets cited. Because each platform runs its own crawler and its own index, being indexed well on Google guarantees nothing on ChatGPT, Claude, or Perplexity. Check your server logs and fix the JavaScript and robots.txt issues that hide your pages. Treat each platform's index as its own separate problem to solve. For the ChatGPT-specific version of this problem, see why Bing indexing matters for ChatGPT visibility. If you want the full picture across every platform without pulling logs yourself, get a free AI visibility assessment and see where your brand stands.