Open your last SEO report. Find the traffic number. Now find out where it came from.

If the answer is SEMrush or Ahrefs, that isn't your traffic. It's an estimate. Produced by a tool that has never had access to your analytics, your server logs, or any of your real data.

And the estimates aren't close. The tools say so themselves. Ahrefs reports a median deviation of 49.52 percent from Google Search Console data. An independent study found SEMrush averages 61.58 percent error. In some cases, reporting 130,000 visits when the actual number was 50,000.

If your vendor is using these numbers in your monthly report, you're making decisions based on data that could be 50 to 60 percent wrong.

How These Tools Estimate Traffic

Understanding why the numbers are wrong helps you see why you should never accept them in a report.

Neither SEMrush nor Ahrefs has access to your actual website data. They don't see your Google Analytics. They don't see your server logs. They don't know how many people actually visited your site.

Instead, they use a formula. They take the keywords your site ranks for, multiply each keyword's estimated search volume by an estimated click-through rate for your ranking position, and add it all up.

(If I'm being honest, when you see it written out like that, it's obvious why the numbers are so far off. Every step in that calculation is an estimate built on top of another estimate.)

The search volume numbers are approximations. The click-through rates are averages that don't account for your specific industry, your brand recognition, or whether Google is showing ads, maps, or AI overviews above your result. And neither tool tracks every keyword your site ranks for. They miss long-tail searches, local variations, and anything not in their database.

The result is always an estimate. Never a fact.

Why This Matters for Your SEO Report

Here's where it gets real.

If your agency reports that organic traffic grew by 30 percent based on SEMrush data, you have no idea if that's true. Your actual traffic in Google Analytics might have grown by 10 percent. Or it might have dropped. The SEMrush number and the real number can point in completely different directions.

I've seen business owners celebrate traffic growth that only existed in SEMrush. And I've seen business owners panic over traffic drops that were nothing more than SEMrush updating their internal algorithm. The estimated traffic line fell even though real traffic stayed exactly the same.

Sound familiar?

If you're paying $5,000 a month or more for SEO, you deserve to see the actual numbers. Not a guess. Not a model. The real data from the tools that track real visitors on your real website.

The Only Sources That Should Be in Your Report

I've been asked many times what should replace the third-party data. And the answer is straightforward.

Google Search Console. This is Google's own tool. It shows you exactly how your site appears in Google search results. Real impressions. Real clicks. Real average positions. Real search terms. This data comes directly from Google. Not modeled. Not estimated. What actually happened.

Google Analytics. This tracks what happens on your website after someone clicks through. Real visits. Real page views. Real session duration. Real conversions. This is your first-party data. It shows exactly what people did on your site.

Together, these two tools give you the complete picture. How people find you in Google and what they do after they arrive. Everything else is supplementary.

It's not about hating SEMrush or Ahrefs. It's about using real data for real decisions.

What SEMrush and Ahrefs Are Actually Good For

I'm not saying these tools are useless. They're extremely valuable. But they need to be used for the right things.

Competitor research. You can't log into your competitor's Google Analytics. So if you want to see what keywords they rank for, what content they're publishing, or where their backlinks come from, SEMrush and Ahrefs are excellent. For comparative purposes, estimated data is the best you'll get, and that's fine.

Keyword research. Both tools have massive keyword databases that help you find new opportunities. The search volume numbers are estimates, but they're useful for identifying relative demand between keywords.

Backlink analysis. Both tools crawl the web and track backlinks. This is useful for understanding your link profile. And it's more reliable than their traffic estimates because it's based on crawling, not modelling.

Technical audits. Both tools offer site audit features that can identify technical issues on your website.

The rule is simple. Use them for research. Use Google Search Console and Google Analytics for reporting. Never mix them up.

What to Tell Your Agency

If I'm being honest, this is one of the easiest conversations to have with your agency. And one of the most important.

Tell them you want all traffic and impression data to come from Google Search Console. All on-site behavior and conversion data from Google Analytics. Call and lead data from your call tracking software.

And tell them that SEMrush and Ahrefs estimates are fine for competitor research and keyword analysis, but they should not appear in the traffic section of your monthly report.

If they push back, ask them why they'd rather show you estimated data when real data is available. I've never heard a good answer to that question.

(And if you're negotiating a new contract, add this as a requirement. All performance reporting must use Google Search Console and Google Analytics as primary data sources. Put it in writing.)

Sources

The accuracy figures referenced in this article come from the following studies.

Ahrefs' own study on traffic estimation accuracy found a median deviation of 49.52 percent from Google Search Console data across 1,635 websites.

Collaborator.pro's independent study across 184 websites found SEMrush had an average error rate of 61.58 percent.

TryAnalyze's comparison of traffic estimation accuracy across multiple tools.

Tech Business News analysis of Ahrefs traffic estimation accuracy.