How AI Crawlers Work

GPTBot, ClaudeBot, CCBot, Google-Extended, and Googlebot — what they fetch, how they parse, and what they miss.

The five AI crawlers SEODiff monitors

SEODiff checks access and behavior for five bots that together represent the major AI training and retrieval pipelines:

Bot	Operator	Purpose	Respects robots.txt
GPTBot	OpenAI	Training data + ChatGPT Browse	Yes
ClaudeBot	Anthropic	Training data for Claude models	Yes
CCBot	Common Crawl	Open web corpus used by many AI labs	Yes
Google-Extended	Google	Gemini training (separate from search)	Yes
Googlebot	Google	Search indexing + AI Overviews	Yes

No JavaScript execution — Most AI crawlers (GPTBot, ClaudeBot, CCBot) do not render JavaScript. They see only the raw HTML response. Content hidden behind client-side rendering is invisible to them.
Plain text extraction — AI crawlers extract text content, not visual layout. They care about semantic HTML, headings, lists, and tables — not CSS styling.
robots.txt compliance — All five bots respect robots.txt Disallow rules. Unlike rogue scrapers, blocking them in robots.txt effectively removes your content from their pipelines.
No link authority — AI crawlers don't use PageRank or link signals. They evaluate content quality, structure, and entity coverage directly.

Server-rendered HTML — Content must be in the initial HTTP response, not injected by JavaScript.
Semantic structure — Headings (h1-h6), lists (ul/ol), tables, and defined sections help AI parse information hierarchically.
Structured data — JSON-LD Schema.org markup gives AI crawlers machine-readable facts (organization, products, FAQs).
Low noise ratio — Pages with minimal boilerplate relative to useful content are easier to extract from.
No access barriers — No robots.txt blocks, no WAF challenges, no CAPTCHA gates.

Client-side rendering (CSR) — React/Angular/Vue SPAs that render content only after JavaScript executes. The crawler sees an empty shell.
WAF / bot protection — Cloudflare Bot Management, Akamai Bot Manager, or similar tools that serve challenge pages to unknown user-agents.
robots.txt blocks — Explicit Disallow: / rules for AI bot user-agents.
Heavy boilerplate — Navigation, footer, sidebar, inline JSON state — burying useful content in noise.