How to Detect AI Crawlers Visiting Your Website
Want to know if GPTBot, ClaudeBot or PerplexityBot are visiting your site? Three practical methods: server logs, robots.txt checks, and a crawler visibility scan.
If AI platforms are citing you, their crawlers visited you first. Detection isn't just curiosity — it tells you whether you're in the game, whether you're accidentally blocking the wrong bots, and whether a bad deploy just cut you off from AI traffic.
Method 1: Check your server logs
Every crawler visit leaves a trace: the User-Agent string. Search your access logs for the AI crawler user agents:
# Look for AI crawler traffic in your access log
grep -iE "GPTBot|OAI-SearchBot|ClaudeBot|Claude-SearchBot|PerplexityBot|Google-Extended|Bytespider" access.log | tail -30What you're looking for is which crawlers visit and how often. A site being indexed by ChatGPT's OAI-SearchBot every day is a site that's in ChatGPT's index. You'll typically also see standard search bots (Googlebot, Bingbot) — those are normal.
Method 2: Check your robots.txt
Logs tell you what did visit. robots.txt tells you what is allowed to visit. The mistake that costs real money: blocking a retrieval crawler (OAI-SearchBot, Claude-SearchBot, PerplexityBot — the ones that get you cited) while thinking you blocked a training crawler (GPTBot, ClaudeBot, Google-Extended). The two are separate decisions.
# Quick check from the terminal
curl -A "OAI-SearchBot/1.0" -I https://yoursite.com
curl -A "PerplexityBot" -I https://yoursite.com200 OK = allowed · 403/4xx = blocked · 503/challenge = your CDN or WAF is interfering.
Method 3: Run a crawler visibility scan
Server logs and manual curls only show one crawler at a time — and there are now 24+ AI crawlers that matter, changing every week. A full scan checks your robots.txt against the whole roster in one shot, tells you exactly which rule is blocking each crawler, and flags accidental misconfigurations.
Run a free 24-crawler check on your site →
Then what?
Detection is the easy part. The value is in the follow-up: if a retrieval crawler is blocked, fix it and re-check; if everything looks fine but you're still not cited, your content may not be structured for AI retrieval (that's a content problem, not a crawler problem). And because crawlers change weekly, a one-time check goes stale fast — that's why continuous monitoring exists.