GPTBot, ClaudeBot, PerplexityBot — each of them has its own crawling logic, scan frequency, and content requirements. So it’s better to consider all these nuances to stay visible to the models that power ChatGPT, Gemini, Claude, and other LLMs.
How does crawling work for different LLMs, what User-Agents do these models use, how often do they access pages, and what exactly do they “read”? — Let’s break it down.
Main LLM Crawlers and Their Specifics
Before optimizing your site for AI exposure, it’s important to understand who exactly is crawling it, so you don’t accidentally block LLM crawlers and instead place links where AI can actually “see” them. Below — the main crawlers collecting data for models like ChatGPT, Claude, Perplexity, Gemini, and what you should know about them.
OpenAI GPTBot
User-Agent: GPTBot/1.0 (+https://openai.com/gptbot)
Purpose: To collect public data for training GPT models (including GPT-4, GPT-4o).
Features:
- Will not scan pages or sections you’ve blocked via robots.txt.
- Ignores restricted or paywalled pages.
- You can allow or block partial/full access to your site.
- High crawl frequency on websites with structured, textual content.
GPTBot prefers content with clear structure and minimal over-optimization. Links in such texts are more likely to be “registered” in AI results. Links within explanations, examples, and lists work better than those in ads or headings.
What blocks crawling:
- Disallow in robots.txt
- No HTTP 200 response (e.g., redirects or 403/404 errors)
- Access blocked by firewall or IP filters
- X-Robots-Tag: noai or noindex headers
To check whether access is open, use OpenAI’s crawler verification tool:
https://platform.openai.com/docs/gptbot
Anthropic ClaudeBot
- User-Agent: ClaudeBot, anthropic-ai
- Designed to collect public content to improve Claude’s responses (based on Constitutional AI).
Features:
- Respects access settings and will not scan pages blocked in your robots.txt file.
- Crawls less aggressively than GPTBot, so the scan frequency is moderate, mainly for high-authority domains.
- Works well with long, informative pages.
- May use general bots like CCBot and fetch data from Common Crawl or other aggregators.
Claude prefers authoritative sources with a natural link profile. If your site is mentioned in hub discussions, comments on analytical or technical articles — your chances of being cited increase. We’ve also noticed that Claude “values” FAQ sections and analytical breakdowns, so this can be a convenient format for link placement.
What hinders crawling:
- Disallow: / in robots.txt for ClaudeBot.
- Pages loaded only via JavaScript (no SSR), so consider server-side rendering or static generation for key pages.
- No external links to the page (low discoverability).
- IP restrictions (the bot operates from cloud infrastructure and might be blocked).
Check accessibility via server logs (look for ClaudeBot). Use tools like Loggly, Logtail, or web analytics with crawler logs to ensure ClaudeBot can “see” your site content.
Google AI (Gemini, Bard) – Google-Extended
- User-Agent: Google-Extended
- Designed to collect data for Gemini models and SGE (Search Generative Experience) features.
Features:
- Crawling occurs through the standard Googlebot, and the data is used for “AI-shortened” responses, not just traditional search.
- You can allow indexing for search but block it for LLMs.
- Access settings are separate from the standard Googlebot.
- Crawl frequency is high and depends on Googlebot activity (sometimes daily).
Si deseas que los enlaces de tu sitio aparezcan en la salida de IA de Google, conviene enfocarse en la autoridad de Google (E-E-A-T), menciones externas y tráfico orgánico.Alta probabilidad de que los enlaces desde guest posts autorizados (foros, materiales relevantes, recursos educativos) sean “absorbidos” en la salida del LLM a través de Google-Extended.
What hinders crawling:
- Disallow: / for Google-Extended.
- No permission set in Google Search Console (for using data in Gemini/SGE).
- Hard-to-access site structure (deeply nested pages, poor internal linking).
- noindex/meta restrictions.
Check robots.txt or Google Search Console → “Settings” → “Content usage for generative AI” to see whether model training is allowed and if access for Google-Extended is active.
AI bots are less likely to reach 3rd–4th level pages, so ensure strong internal linking to help crawlers discover such content.
PerplexityBot
- User-Agent: PerplexityBot
- Scans websites to generate responses on Perplexity.ai.
Features:
- Actively cites sources with links and displays them directly in the results with clickable URLs.
- Often extracts 1–2 paragraphs of relevant information.
- Respects access rules in robots.txt, but not always clearly (may still scan formally disallowed pages or access them via a different User-Agent through proxies or with obscure identification).
- Crawls more actively than GPTBot, especially on sites related to technology, business, and analytics.
This is the most useful bot for driving traffic from AI — Perplexity displays all sources with links in its results. The format “thematic query – short analysis – link to site” is ideal for being included in its responses. It works great if you have an analytical blog, expert articles, or case studies with data.
What hinders crawling:
- Disallowed in robots.txt
- JS-generated content without SSR (the bot only processes HTML from the initial render)
- Login or paywall access only
- Low domain trust or lack of backlinks
You can check if the bot can access a page via raw HTML:
curl -A “PerplexityBot” https://yourwebsite.com/yourpage/.
You can also monitor crawler traffic using log files or Cloudflare Logs (check the user-agent).
Common Crawl / Amazon CCBot
- User-Agent: CCBot/2.0 (+http://commoncrawl.org/faq/)
- Designed for large-scale web crawling and data collection later used by open LLMs (such as Meta, Amazon, Mistral, etc.).
Features:
- Archives all public content (only open-access text).
- Often serves as “raw material” for many models simultaneously.
- May appear on websites without clear affiliation with a specific LLM.
- Crawl frequency: once every 30–60 days.
If your content ends up in Common Crawl datasets, it may be used by dozens of LLMs. This means even outdated but deep-linked content can be “remembered” by models and appear in answers years later. Therefore, it’s worth creating evergreen content with backlinks.
What hinders crawling:
- Disallow: / for CCBot in robots.txt
- Content available only with authentication
- Too many redirects or slow page load times
- Lack of external mentions — CCBot primarily follows links from other sites
Check if your site is in Common Crawl: https://index.commoncrawl.org/
You can also test in server logs: filter for CCBot
If a site is indexed by Common Crawl or actively crawled by GPTBot/PerplexityBot, link placements on such sites have a higher chance of appearing in AI responses. It’s useful to check whether platforms are listed in the Common Crawl Index or active in logs from GPTBot, ClaudeBot, etc.
Additionally: Technical checklist for a crawl-ready website
- Crawling allowed for AI bots in robots.txt
- sitemap.xml is up to date
- Content is accessible without scripts
- Schema.org markup (especially for FAQ, product, article)
- Log files checked for AI crawler requests
- Meta tags without noai, noindex
- Optimized page load (Core Web Vitals)
Conclusion
Each crawler — GPTBot, ClaudeBot, PerplexityBot, Google-Extended, or CCBot — has its own logic and limitations. Sometimes it’s enough to allow access in robots.txt, other times external mentions, structured HTML, or clean semantics matter. And if even one technical barrier isn’t removed (e.g., the page is in noindex, or loads only via JS), no AI bot will “see” it.
So, at the intersection of SEO and AI, a new type of visibility is emerging. That’s why it’s worth checking platforms not only for trustworthiness but also for accessibility to AI crawlers. Then your links will work both for SEO and appear in ChatGPT, Gemini, Perplexity responses — and bring in traffic from there too.
