What Ahrefs does and why it wants to crawl your site

Ahrefs is a web crawler owned by a company that sells SEO and competitive analysis tools. Its bot visits websites automatically to collect data about links, content, and site structure. That data feeds into reports that SEO professionals and marketers buy — they use it to see which websites link to their competitors, what keywords those sites rank for, and how a site's authority has changed over time.

Ahrefs crawls your site whether you want it to or not, unless you actively block it. The company argues that blocking them means you won't appear in their reports, which could put you at a disadvantage if your competitors use Ahrefs to research the market you're in. That argument is partly true, but it's also partly their sales pitch.

The real question is whether the crawling itself costs you anything, and whether you care about appearing in a third-party tool that you don't pay for and didn't ask to use.

Key Takeaways

  • Ahrefs crawling uses a small but measurable amount of your server resources, which matters more on shared hosting or sites with tight bandwidth limits than on dedicated servers.
  • Blocking Ahrefs does not hurt your Google rankings — Google's crawler is separate, and blocking one bot does not signal anything to search engines.
  • You block Ahrefs by adding their bot name to your robots.txt file or by using your hosting control panel's bot-blocking tools, a change that takes minutes.
  • If you're a small site on shared hosting, blocking Ahrefs saves resources; if you're a business that uses Ahrefs reports yourself, blocking it means you won't see your own site in their data.
  • Ahrefs respects robots.txt when it's configured correctly, so blocking them is reliable — they do not try to work around it.

The actual cost of Ahrefs crawling your site

Every time a bot visits your site, it uses server resources: bandwidth, CPU time, and database queries if your pages are dynamic. For most websites, Ahrefs crawling is a tiny fraction of total traffic and barely registers. A site getting 10,000 human visitors a day will see Ahrefs as maybe 50 to 200 requests, depending on how much content you have.

The cost becomes real on shared hosting plans where you have a bandwidth cap or a CPU limit. If you're on a $5-a-month shared host and you're already near your monthly bandwidth limit, Ahrefs crawling can push you over and trigger overage charges or temporary slowdowns. On a dedicated server or a modern cloud host with unlimited bandwidth, it's noise.

The other cost is indirect: crawlers compete with real users for your server's attention. If your site is slow and you're trying to figure out why, Ahrefs crawling is one of several bots that might be making it worse. Blocking unnecessary bots can free up resources for the visitors who actually matter to your business.

Blocking Ahrefs does not affect your Google rankings

This is the fear that keeps most people from blocking any bot: "Won't Google penalize me?" The answer is no. Google's crawler is completely separate from Ahrefs. Blocking Ahrefs tells Google nothing about your site, and Google does not care whether Ahrefs can see you.

Google ranks sites based on content, links from other sites, user behavior, and technical factors like page speed and mobile-friendliness. None of those things change when you block Ahrefs. Your site will rank exactly the same whether Ahrefs can crawl it or not.

The only thing that changes is that Ahrefs reports will not include data about your site. If you use Ahrefs yourself to research competitors, you won't see your own site in their database. That's a real limitation, but it's not a ranking penalty.

How to block Ahrefs in robots.txt

The standard way to block any bot is through your robots.txt file, a plain text file that sits in your site's root directory and tells bots what they can and cannot crawl. To block Ahrefs, add these lines to your robots.txt:

User-agent: AhrefsBotDisallow: /

That tells Ahrefs's bot to not crawl anything on your site. The forward slash means "everything." If you want to block Ahrefs but allow other bots, add those lines without removing the rest of your robots.txt file.

To edit robots.txt, log into your hosting control panel (cPanel, Plesk, or whatever your host uses), find the file manager, navigate to the root directory of your domain, and open or create robots.txt. Add the lines above, save, and you're done. The change takes effect when ready — Ahrefs respects robots.txt and will stop crawling within a day or two.

If you're not comfortable editing files, most hosting control panels have a built-in bot manager or security tool that lets you block specific bots through a checkbox interface. Check your host's documentation or contact their support to find it.

When blocking Ahrefs makes sense

Block Ahrefs if you're on shared hosting with limited bandwidth or CPU, or if you're running a small site that doesn't benefit from appearing in SEO research tools. A personal blog, a local service business, or a site that doesn't compete on search rankings has no reason to let Ahrefs crawl.

Block Ahrefs if you're concerned about privacy and don't want a third party collecting detailed data about your site's structure and content. Ahrefs data is sold to competitors and researchers, so blocking it means you're not part of that dataset.

Do not block Ahrefs if you use Ahrefs reports yourself to research your market. If you pay for Ahrefs, you want your own site in their database so you can see how you compare to competitors and track your own backlinks over time.

Other bots worth blocking or allowing

Ahrefs is one of many crawlers. SEMrush, Moz, and SimilarWeb run their own bots that work the same way. If you want to block all of them, add their bot names to robots.txt the same way you block Ahrefs. The names are SemrushBot, MJ12bot (Majestic), and SimilarWeb.

You should almost never block Google's bot (Googlebot) or Bing's bot (Bingbot). Those crawlers are how search engines index your site, and blocking them means you won't appear in search results at all.

Social media bots like the Facebook crawler and Twitter crawler are usually safe to allow — they help your links look better when people share them. If you're concerned about traffic from bots in general, focus on the SEO research bots, which are the ones that use the most resources.

What happens if you block Ahrefs and change your mind

Blocking is reversible. If you block Ahrefs and later decide you want them to crawl your site again, remove those lines from robots.txt and save the file. Ahrefs will resume crawling within a few days and will start collecting data about your site again.

There's no penalty for changing your mind, and Ahrefs doesn't hold a grudge. They're a bot — they follow instructions and move on. If you unblock them, they treat your site as if the block never happened.

Frequently Asked Questions

Will blocking Ahrefs hurt my SEO?

No. Google's crawler is separate from Ahrefs, and blocking Ahrefs does not affect how Google ranks your site. Your rankings will not change. The only effect is that Ahrefs reports will not include data about your site.

Can Ahrefs crawl my site even if I block them in robots.txt?

Ahrefs respects robots.txt, so if you block them correctly, they will not crawl your site. Some bots ignore robots.txt, but Ahrefs is not one of them. If you want to be absolutely certain, you can also block their IP addresses at the server level, though robots.txt is usually enough.

What's the difference between blocking Ahrefs and blocking all bots?

Blocking Ahrefs blocks only their bot. Blocking all bots means adding "Disallow: /" under "User-agent: *", which tells every bot to stay away. That includes Google, so you should never do it unless you want your site completely hidden from search engines.

Does Ahrefs charge me if their bot crawls my site?

No. Ahrefs crawling is free for you — they pay for the bandwidth. The only cost is the tiny amount of server resources their bot uses, which matters only on very limited hosting plans.

If I block Ahrefs, will competitors see my site in Ahrefs reports?

No. If you block Ahrefs, your site will not appear in any Ahrefs reports, including reports your competitors run. That's the trade-off: you save resources, but you're also invisible to people researching your market through Ahrefs.