What is AhrefsSiteAudit? Ahrefs's SEO crawler

17 of the 379 major websites we measure block AhrefsSiteAudit in robots.txt (4%). 7 of those sites name it directly in their robots.txt; the rest are covered by a wildcard rule.

Key facts

What blocking AhrefsSiteAudit does

Ahrefs says it obeys robots.txt and crawl delay by default, and that website owners can request it to disobey them on their own sites.

How to allow or block AhrefsSiteAudit

Add one of these groups to the robots.txt file at the root of your domain. It is a stated preference that well-behaved crawlers read, not an enforcement mechanism.

User-agent: AhrefsSiteAudit
Disallow: /

User-agent: AhrefsSiteAudit
Allow: /

AhrefsSiteAudit user agent string

The string Ahrefs documents. Version numbers can change, so match on the name.

Mozilla/5.0 (compatible; AhrefsSiteAudit/6.1; +http://ahrefs.com/robot/site-audit)

How to verify a request is really AhrefsSiteAudit

Anyone can put a crawler's name in a user agent string, so the name alone proves nothing. Ahrefs says it crawls from publicly published IP ranges, and that the reverse DNS suffix of those addresses is always ahrefs.com or ahrefs.net.

How to whitelist AhrefsSiteAudit in a firewall or CDN

robots.txt only states a preference. A firewall, CDN or bot protection service can still refuse the request, and the crawler then gets an error even though robots.txt allows it.

1. Check that no group in your robots.txt blocks it, using the rule above.
2. Add an allow rule in your firewall or CDN that matches the name in the user agent. Keep the rule narrow, because anyone can copy a name.
3. Check your server logs for a 200 response from AhrefsSiteAudit afterwards.

On Cloudflare, also check AI Crawler and Agent access policies, which can block search, agent and training traffic across a site.

Why AhrefsSiteAudit gets a 403 or 405 error

A 403 means the server refused the request, which usually points to a firewall or bot rule. A 405 means the server refused the request's method, so check any rule that only permits certain methods. A crawler that obeys robots.txt won't request a page it is told to avoid, so an error in your logs points to your server's configuration. To stop it deliberately at the server, this nginx rule returns a 403:

if ($http_user_agent ~* "AhrefsSiteAudit") {
    return 403;
}

Who blocks AhrefsSiteAudit, by sector

Sites blocking AhrefsSiteAudit

academia.edu, barrons.com, disneyplus.com, flickr.com, hackernoon.com, hulu.com, imdb.com, instacart.com, marketwatch.com, netflix.com, reddit.com, reuters.com, spiegel.de, theguardian.com, theregister.com, thetimes.co.uk, wsj.com.

Sites that allow AhrefsSiteAudit by name

forbes.com, pinterest.com, sciencedirect.com, slate.com, unsplash.com.

Other Ahrefs crawlers

AhrefsBot (SEO link index).

See all 30 AI crawlers, the rule change log or the full study. Being reachable is only the first step: how AI search engines choose what to cite covers the rest.

IndexHalo. "AhrefsSiteAudit block rate across major websites." Measured 3 November 2026. https://www.indexhalo.com/ai-crawlers/ahrefssiteaudit/

<a href="https://www.indexhalo.com/ai-crawlers/ahrefssiteaudit/">AhrefsSiteAudit block rate across major websites, IndexHalo</a>