How AI Crawlers Use Your Website

Published: June 6, 2026

AI crawlers are bots that read your website so AI assistants like ChatGPT, Gemini, Perplexity, and Claude can answer questions about it. They are not the same as the search bots you already know. Understanding what they fetch and how they decide whether to mention you is the difference between being the answer an AI gives and being skipped for a competitor.

How AI crawlers differ from search bots

Traditional search bots like Googlebot exist to build an index. They crawl your pages, store them, and rank them so a person can find a link in a results list. The goal is a ranked list of pages.

AI crawlers have a different job. They gather content so a language model can summarize it and recommend it inside a conversation. There is no list of ten blue links. There is one answer, and either your business is named in it or it is not. That changes what matters: clear, factual, machine-readable content beats keyword-stuffed pages built to rank.

The major AI crawlers

Four crawlers cover most of the AI traffic you will see today. Each one identifies itself with a user-agent string in your server logs.

• GPTBot (OpenAI) — collects content that helps power ChatGPT and OpenAI models.
• ClaudeBot (Anthropic) — gathers content for Claude.
• PerplexityBot (Perplexity) — feeds the Perplexity answer engine, which cites sources directly in its responses.
• GoogleOther (Google, for Gemini and AI Overviews) — Google uses this agent for AI products like Gemini and the AI answers in search, separate from the main Googlebot search crawl.

There are more (Google-Extended, Applebot-Extended, Bytespider, and others), but if you account for these four you cover the assistants most people actually use.

What they fetch

When an AI crawler visits, it does not read every page at random. It looks for the files that describe your site fastest, then follows links from there.

• llms.txt — the markdown summary at your site root. If it exists, this is the cleanest description of your site the crawler can get, so it is often read first.
• robots.txt — the access rules. The crawler checks whether it is allowed to read your pages before it does.
• sitemap.xml — the list of public pages worth reading, so the crawler does not have to discover them link by link.
• Your homepage and key pages — the actual content, including headings, body text, and JSON-LD structured data.

How a crawler decides whether to cite you

Getting crawled is not the same as getting cited. A crawler reads your site, but the model decides whether to name you when a user asks a question. These factors raise the odds that it picks you.

• Clear, factual descriptions: content that states what you do in plain language is easy to quote. Vague marketing copy is not.
• Machine-readable metadata: a valid llms.txt and JSON-LD structured data give the model facts it can repeat with confidence, instead of guessing from page layout.
• Self-contained answers: a paragraph that fully answers one question can be lifted straight into a response. Content that only makes sense after reading the whole page is harder to cite.
• Consistency: when your llms.txt, structured data, and page copy all say the same thing, the model trusts the answer more.

How often they visit

AI crawlers visit periodically, not in real time. There is no fixed schedule, and it varies by crawler and by how often your site changes. A page you update today may not be re-read for days or weeks.

This has a practical consequence. AI assistants cite whatever the crawler last saw. If you changed your pricing last week but the crawler read the old number, the AI will keep repeating the old price until the next visit. Keeping your llms.txt and key pages accurate matters precisely because you do not control when the next crawl happens.

How to verify they are visiting

You can confirm AI crawlers are reaching your site by checking your server access logs for their user-agent strings. On a typical Linux server with Apache or Nginx, the logs live in /var/log.

# Count AI crawler hits in an Apache access log
grep -E "GPTBot|ClaudeBot|PerplexityBot|GoogleOther" \
  /var/log/apache2/access.log | wc -l

# See which paths GPTBot requested
grep "GPTBot" /var/log/apache2/access.log | awk '{print $7}' | sort | uniq -c

The user-agent strings look roughly like the examples below. Seeing them in your logs confirms the crawler reached your server.

Mozilla/5.0 ... (compatible; GPTBot/1.2; +https://openai.com/gptbot)
Mozilla/5.0 ... (compatible; ClaudeBot/1.0; [email protected])
Mozilla/5.0 ... (compatible; PerplexityBot/1.0; +https://perplexity.ai/perplexitybot)

Should you block them?

You can block AI crawlers in robots.txt with a Disallow rule for each user-agent. For most sites, you should not. Blocking an AI crawler means the assistant cannot read your content, so it cannot recommend you. You remove yourself from answers people are actively asking for.

There are real reasons some sites block them: protecting paywalled content, keeping proprietary data out of training sets, or controlling server load. If none of those apply, allowing AI crawlers is the default that helps you. If you do want to block, do it per path, not site-wide, so public pages stay readable while private sections stay closed.

# Allow AI crawlers, block only a private section
User-agent: GPTBot
Allow: /
Disallow: /members/

User-agent: ClaudeBot
Allow: /
Disallow: /members/