OnCrawl user agent
Operated by Oncrawl
OnCrawl is the crawler of the Oncrawl technical SEO platform.
The OnCrawl bot at a glance
- OnCrawl is operated by Oncrawl and fetches pages to power a specific product feature.
- The robots.txt token for OnCrawl is OnCrawl.
- Blocking an SEO tool crawler has no effect on Google or Bing rankings.
- OnCrawl robots.txt support: Not documented.
- Recommendation for Generative Engine Optimization (GEO): Your choice.
What is OnCrawl?
OnCrawl crawls sites that Oncrawl users audit.
Oncrawl has not kept a public bot page online.
Should you block OnCrawl?
Blocking OnCrawl is a business decision: it protects your content but can lower how well AI products know your brand.
| Effect on search rankings | Blocking an SEO tool crawler has no effect on Google or Bing rankings. |
|---|---|
| Effect on AI visibility | No effect on AI answers. Blocking hides your pages and backlinks from that SEO tool, including from competitors who use it, and breaks your own audits in that tool. |
| Follows robots.txt | Not documented |
| Recommendation | Your choice |
How to block or allow OnCrawl
Put the robots.txt rule in the file at the root of every domain and subdomain, for example https://example.com/robots.txt. The token OnCrawl is matched case-insensitively. robots.txt alone may not stop OnCrawl, so add the Nginx, Apache or Cloudflare rule as well.
robots.txt: block
# Block OnCrawl
User-agent: OnCrawl
Disallow: /robots.txt: allow
# Allow OnCrawl
User-agent: OnCrawl
Allow: /robots.txt: partial
# Keep OnCrawl out of private areas only
User-agent: OnCrawl
Disallow: /wp-admin/
Disallow: /cart/
Disallow: /checkout/
Disallow: /my-account/
Allow: /Nginx
# Nginx: return 403 to OnCrawl
if ($http_user_agent ~* "(OnCrawl)") {
return 403;
}Apache
# Apache .htaccess: return 403 to OnCrawl
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} (OnCrawl) [NC]
RewriteRule .* - [F,L]Cloudflare WAF
# Cloudflare > Security > WAF > Custom rule, action: Block
(http.user_agent contains "OnCrawl")How to verify real OnCrawl traffic
Oncrawl publishes no IP list or reverse DNS pattern for OnCrawl, so the user agent cannot be verified. Anyone can send the same string. Rate-limit unusual volume instead of trusting the name.
How to find OnCrawl in your server logs
Search the web server access log for the token. The command below counts OnCrawl requests per URL on Nginx or Apache.
grep -i "OnCrawl" access.log | awk '{print $7}' | sort | uniq -c | sort -rn | head -20For a full report per AI bot, upload the log to the AI Log File Analyzer, a free tool by Justin Hà.
OnCrawl user agent string
The full user agent Oncrawl publishes for OnCrawl. Version numbers such as Chrome/W.X.Y.Z change over time, so match the token, not the whole string.
CCBot/2.0 (http://commoncrawl.org/faq/)OnCrawl FAQ
OnCrawl identifies itself with the robots.txt token "OnCrawl". A typical request header reads: CCBot/2.0 (http://commoncrawl.org/faq/)
Oncrawl has not documented how OnCrawl treats robots.txt. Add a robots.txt rule and back it with a server rule if the traffic matters to you.
Blocking an SEO tool crawler has no effect on Google or Bing rankings. No effect on AI answers. Blocking hides your pages and backlinks from that SEO tool, including from competitors who use it, and breaks your own audits in that tool.
Add two lines to the robots.txt file at the root of each domain and subdomain: "User-agent: OnCrawl" followed by "Disallow: /". The token is case-insensitive. Changes can take up to 24 hours to be picked up.
Not reliably. Oncrawl publishes no IP list or reverse DNS pattern for OnCrawl, so anyone can send the same user agent. Rate-limit unusual volume instead of trusting the name.
Search your server access log for "OnCrawl", for example with: grep -i "OnCrawl" access.log. The AI Log File Analyzer by Justin Hà counts visits per AI bot from an uploaded log file.
Sources: Public bot registry. Last reviewed by Justin Hà.
See which of these bots actually reach your website
The AI Log File Analyzer by Justin Hà counts visits from GPTBot, ClaudeBot, PerplexityBot and other AI crawlers in your server log, for free. The GEO Technical Package sets up robots.txt, llms.txt and crawler access for AI search.
