How LLMs Crawl Your Website: A Technical Guide for SEOs
Posted on June 28, 2026
As AI-powered search engines like ChatGPT, Perplexity, and Google AI Overviews become primary information sources, understanding how large language models (LLMs) crawl and index your website is critical for maintaining visibility. Unlike traditional search engines that rank pages by keywords and backlinks, LLMs evaluate content differently — they look for structured, authoritative, and entity-rich information they can confidently cite.
How AI Crawlers Differ from Traditional Search Bots
Traditional search bots (Googlebot, Bingbot) crawl your site to build an index of pages, then rank them algorithmically. AI crawlers like GPTBot, ClaudeBot, and PerplexityBot crawl your site to extract knowledge — they want to understand entities, relationships, and facts they can reference when answering user questions.
- GPTBot (OpenAI) — Crawls to train models and provide real-time citations in ChatGPT. Respects robots.txt and CORS headers.
- ClaudeBot (Anthropic) — Gathers content for Claude citations. Known to crawl aggressively; ensure your server can handle the load.
- PerplexityBot — Feeds Perplexity AI's real-time search. Prioritizes pages with recent updates and clear factual content.
- Google-Extended — Controls whether your content is used for Google AI Overviews and Bard training.
- CCBot (Common Crawl) — Feeds multiple AI models. Blocking CCBot can significantly reduce your LLM citation probability.
Optimizing robots.txt for AI Crawlers
Your robots.txt file is the first thing AI crawlers check. Here is how to configure it for maximum AI visibility while maintaining control:
User-agent: GPTBot Allow: / User-agent: ClaudeBot Allow: / User-agent: PerplexityBot Allow: / User-agent: Google-Extended Allow: / User-agent: CCBot Allow: / User-agent: * Allow: /
Use Scanly to audit your robots.txt configuration and check which AI crawlers are currently allowed or blocked.
The llms.txt File: Your Site's AI Resume
Introduced in 2025, llms.txt is a simple text file that provides AI crawlers with a curated overview of your website. Think of it as a robots.txt for LLMs — it tells AI systems what your site is about and which pages matter most.
# Scanly - AI Website Audit Tool > AI-powered website auditor for SEO, performance, accessibility, and security. ## Core pages - Features: https://scanly.site/features - Pricing: https://scanly.site/pricing - Sample Report: https://scanly.site/sample-report - GEO Audit: https://scanly.site/solutions/ai-search-optimization-audit
Scanly checks for the presence and quality of your llms.txt file during its GEO audit.
Content Structure That LLMs Love
LLMs prefer content that is easy to parse and extract facts from. Here is what makes content LLM-friendly:
- Clear entity definitions — Explicitly state what your product does, who it is for, and what problem it solves. Use Organization, Product, and SoftwareApplication schema.
- Factual, well-sourced claims — LLMs are trained to prefer content backed by data, statistics, and authoritative references.
- Semantic HTML structure — Proper heading hierarchy (H1 → H2 → H3), semantic elements (<article>, <section>, <nav>), and descriptive link text.
- FAQ sections — LLMs frequently use Q&A content to answer user queries. Mark up your FAQs with
FAQPageschema for maximum citation probability. - Fresh, regularly updated content — AI crawlers prioritize recently updated pages, especially for real-time queries in Perplexity and ChatGPT search.
Monitoring Your LLM Visibility
Unlike Google Search Console which shows your traditional search performance, there is no centralized dashboard for AI citation data. However, you can:
- Manually test by asking ChatGPT, Perplexity, or Gemini questions related to your niche and checking if your site is cited.
- Use Scanly to audit your site's technical foundations for AI visibility — schema accuracy, llms.txt presence, robots.txt AI crawler permissions, and content authority signals.
- Monitor your brand mentions across AI platforms using social listening tools.
For a deeper dive into GEO strategy, read our Generative Engine Optimization guide.
Frequently Asked Questions
What AI crawlers should I allow in my robots.txt?
For maximum AI search visibility, you should allow GPTBot (used by ChatGPT), ClaudeBot (used by Claude/Anthropic), PerplexityBot (used by Perplexity AI), and Google-Extended (used by Google AI Overviews). You can manage these individually in your robots.txt file using their user-agent tokens.
Can I block AI crawlers from my site?
Yes, you can block AI crawlers by adding their user-agent tokens to your robots.txt file. For example, "User-agent: GPTBot Disallow: /" will block OpenAI's crawler. However, blocking AI crawlers means your content won't be cited by ChatGPT, Perplexity, or other AI search engines.
How do LLMs decide which content to cite?
LLMs prioritize content that is well-structured with clear semantic HTML, has accurate schema markup (JSON-LD), comes from authoritative domains with strong brand signals, and provides factual, well-sourced information. Structured data, entity clarity, and content freshness are key ranking factors for AI citation.
What is llms.txt and how do I create one?
llms.txt is a plain text file that provides AI crawlers with a structured overview of your website. It lists your key pages, content categories, and what your site does. Place it at the root of your domain (e.g., https://yoursite.com/llms.txt) and use simple markdown formatting. Scanly checks for llms.txt during its GEO audit.
Start Optimizing for LLM Crawlers Today
As AI search adoption grows, being cited by LLMs will become as important as ranking on Google's first page. The foundations are the same — great content, proper structure, and technical excellence — but the optimization signals are different. Run a free GEO audit to see how LLM-ready your site is today.
See how LLM-friendly your site is
Scanly checks AI crawler permissions, llms.txt, schema accuracy, and content authority.
Related: GEO Guide · LLM Seeding · Rank in AI Search · GEO Audit Tool · Scanly Features