AhrefsBot and Other SEO Crawlers: Block Them or Not?

Your server logs show thousands of requests from AhrefsBot, SemrushBot, and similar crawlers every month. They eat bandwidth, add load to your infrastructure, and — according to your analytics — produce exactly zero conversions. The instinct is to block them all. That instinct is half right, and the half you get wrong can cost you leads you will never see.

What AhrefsBot Actually Does

AhrefsBot is the web crawler operated by Ahrefs, a company that sells SEO and backlink analysis tools. The bot crawls the web to build the link index that powers Ahrefs’ products: when someone runs a backlink report, competitor analysis, or site audit in the tool, they are querying the data AhrefsBot collected. The same model applies to its peers — SemrushBot feeds Semrush, DotBot feeds Moz, MJ12bot feeds Majestic, and PETALBOT feeds Ahrefs’ content-analysis product.

Three things matter about this model:

• The data has commercial value to third parties. Agencies, competitors, journalists, and yes, potential customers, pay to see who links to your site, what keywords you rank for, and how your content is structured.
• The crawl does not directly send traffic. Being indexed by AhrefsBot does not put you in any search results. Nobody clicks from an Ahrefs report to your site (with a narrow exception around backlink referral — people do find your site by studying your competitors’ link profiles, but that happens off your server).
• The crawl costs you real resources. Depending on your site’s size and server, a major SEO crawler can account for anywhere from a small trickle to hundreds of thousands of requests per month.

This is the trade-off in one sentence: you pay bandwidth and server load so that other people can see your site’s data in an SEO tool. Whether that trade is worth it depends entirely on who those “other people” are.

The Bot Landscape: Who’s Hitting Your Server and Why

Before deciding who to block, you need to know who’s at the door. These are the crawlers most commonly found in mid-market site logs:

Bot	Operated by	What it collects	What happens if you block it
AhrefsBot	Ahrefs	Backlinks, referring pages, outbound links	Your site disappears from Ahrefs’ link index; anyone analyzing your backlink profile sees a gap or nothing
SemrushBot	Semrush	Keywords, rankings, backlinks	Your visibility data in Semrush goes stale or missing — including in reports your leads may run
DotBot	Moz	Link data	Same as above, for Moz’s index
MJ12bot	Majestic	Link graph data	Excluded from Majestic’s historic link database
PETALBOT	Ahrefs (content tools)	Page content for content analysis	Your pages are excluded from content-discovery datasets
GPTBot and similar AI crawlers	AI companies	Page content for model training / retrieval	Your content is not used in AI training or retrieval systems; you get nothing in return (unless a partnership exists)
Googlebot	Google	Everything needed for search indexing	Never block this. Blocking it directly harms your organic traffic

The critical distinction in that table: Googlebot is not an SEO-tool crawler. A recurring and expensive mistake is treating all bots as interchangeable and blocking indiscriminately.

The Question Everyone Gets Wrong: Does Blocking AhrefsBot Affect Google Rankings?

No. Blocking AhrefsBot has no effect on your rankings in Google or any other search engine. Search engines rank pages using their own crawlers and their own ranking systems. AhrefsBot does not feed Google’s index, and Google does not consult Ahrefs’ link database to decide where you rank. The two ecosystems are entirely separate.

This matters because you will find forum threads and even some agency blog posts implying the opposite — that blocking SEO crawlers somehow “hides” signals Google needs. It does not. The popular advice you should not follow is the blanket directive to “block all bots to save bandwidth” found in various hosting optimization guides. If that guide’s robots.txt example lumps AhrefsBot in with Googlebot, following it can deindex your site. Always read the full user-agent list before copying a snippet.

So the ranking question is settled. The real question is a business one: who is looking at your data in SEO tools, and do you want them to see it?

Who Benefits From Your Data Being Visible

Here is the part most articles skip. The people querying Ahrefs and Semrush for data about your domain are not only your competitors doing competitive research. They include:

• Prospective customers evaluating you. A marketing lead about to sign a contract with your company may run your domain through an SEO tool — exactly the way a savvy buyer vets a vendor. A domain with zero visible backlink data can read as either “new” or “suspicious,” and the buyer has no way to tell which.
• Journalists and writers sourcing sources. Link indexes are a common way to find authoritative sites in a niche to cite. If you are invisible, you cannot be found this way.
• Partners and affiliates doing due diligence. Anyone considering a partnership or affiliate arrangement will often check your organic footprint.
• Investors and acquirers. Due-diligence processes in e-commerce and SaaS routinely include organic visibility checks.

The consequence of blocking: your site effectively goes dark in third-party reports. Your competitor’s report shows them with 4,000 referring domains and you with “no data.” You do not lose rankings — you lose credibility in rooms you are not in.

Reverse the frame and this cuts the other way too: the same visibility you grant others, you enjoy when analyzing them. If every site blocked these crawlers, the entire competitive-intelligence layer of the industry would collapse. Most companies are better served staying in the dataset.

When Blocking Genuinely Makes Sense

Visibility is not free, and for some sites the cost exceeds the benefit. Blocking is a rational choice when:

• Your infrastructure is genuinely strained. If crawlers are causing measurable performance problems — slow response times, CPU saturation, hosting overage charges — the business case changes. A slow site hurts real users and real rankings; missing backlink data hurts nobody measurably.
• You have nothing to hide but nothing to show either. A pure utility site or internal-facing service with no marketing function gains nothing from appearing in SEO tools.
• You are being targeted by abusive crawlers. Some operators spoof legitimate bot names or ignore robots.txt entirely. That is not a visibility decision anymore; it is an abuse-mitigation decision, and aggressive blocking is appropriate.
• Crawl volume is wildly disproportionate. A 50-page site receiving tens of thousands of crawler hits per month is being crawled inefficiently. First try Crawl-delay or rate-limiting; block only if that fails.

A useful heuristic: if blocking the crawler is a cost decision, block it. If it is a perception decision, think twice — perception decisions in marketing rarely go the way people expect.

How to Block AhrefsBot Properly (and the Trap to Avoid)

Ahrefs, like Semrush and most major SEO tool providers, respects the robots.txt exclusion protocol. Blocking is straightforward and honored. Add this to your robots.txt file at the root of your domain:

User-agent: AhrefsBot
Disallow: /

To block several at once, list each user-agent separately — robots.txt has no meaningful “block these five” grouping syntax across different bots, so repeat the pattern:

User-agent: SemrushBot
Disallow: /

Two practical details:

1. De-indexing is not instant. After blocking, data about your site persists in tool databases until the next refresh cycle, which typically takes days to weeks depending on the vendor’s update schedule. Expect your data to fade out, not vanish overnight.
2. Test before you celebrate. Use a robots.txt validator and confirm the file returns HTTP 200 at yourdomain.com/robots.txt. A robots.txt served with an error status may be ignored or, worse, misinterpreted.

The trap: robots.txt is a request, not a lock. Well-behaved SEO crawlers obey it; scrapers, spam bots, and badly written scripts do not. If your actual problem is abusive traffic, robots.txt will do nothing — see the next section.

If Robots.txt Is Not Enough: Server-Level Throttling and Firewalls

For crawlers that ignore robots.txt, or when you need guaranteed enforcement, move the decision to the server layer:

• Rate limiting. Most web servers and CDNs support per-IP or per-user-agent request limits. A common starting point is allowing a modest number of requests per minute per client and returning 429 Too Many Requests above that threshold. Legitimate SEO crawlers generally slow down when throttled politely.
• Verify by reverse DNS. A real AhrefsBot request resolves back to an Ahrefs-owned IP range; anyone can name their script “AhrefsBot.” Reverse-DNS verification is the standard way to separate genuine crawlers from spoofers. Cloudflare and comparable services offer verified-bot categories so you can allowlist legitimate crawlers and challenge everything else.
• Firewall rules. For persistent abuse, block at the firewall or WAF level rather than the application level, so junk traffic never reaches your application code.

Escalate in this order: robots.txt first (free, respectful, sufficient for most cases), rate limiting second, firewall blocking third. Starting with firewall blocks against a compliant crawler is overkill and burns goodwill — some tool vendors check whether sites have blocked them and adjust crawl behavior accordingly.

The Decision Framework: Block or Not?

Run your situation through this sequence:

1. Is the bot verified and robots.txt-compliant, or is it spoofing/abusive? Abusive → throttle and block at the server. Compliant → continue.
2. Is the crawl load measurably hurting performance or costs? If yes, try Crawl-delay or rate limits before a full block. If performance is fine, continue.
3. Does your business benefit from being visible in competitive-analysis tools? If you sell to marketers, agencies, or anyone who vets vendors online, the answer is almost certainly yes → do not block. If you are a private company with no organic-marketing ambitions and real infrastructure strain → block selectively and consciously.
4. Is this Googlebot or another search engine crawler? Do not block. Full stop. Whatever problem you think you are solving, blocking search crawlers creates a bigger one.

The one-sentence version: blocking ahrefsbot never touches your Google rankings, but it decides whether strangers vetting your company see a credible organic footprint or a blank page — so make that call deliberately, with data from your own server logs, rather than by copying a robots.txt snippet you found in a hosting forum.

Related reading

• Content strategy — scope, method and what we measure.
• AI search optimisation
• SEO Reporting: Building a Report Someone Actually Reads
• Website Traffic Rankings: How Accurate Are Those Lists?