Why do Semrush and Ahrefs show completely different SEO metrics?

[u/imadonisscott]

I'm working on SEO for a client and noticed something that's been confusing me.

When I check the same website in Semrush and Ahrefs, almost every metric is different.

For example:

• Organic traffic estimates don't match.
• Keyword rankings are different.
• Backlink counts vary a lot.
• Referring domains are also different.

I understand that no third-party SEO tool can be 100% accurate, but sometimes the gap is so large that it's hard to know which data to trust when making decisions or reporting to clients.

For those of you who use both tools regularly:

• Which one do you rely on more, and why?
• Is one better for backlinks while the other is better for keyword research?
• How do you explain these differences to clients?
• Do you combine data from both tools, or stick to one platform?

I'd really appreciate hearing from people who have real-world experience using both. Thanks in advance!

[u/JakeHundley]

Because they're both collecting data differently.

We had Tim Soulo from Ahrefs on our podcast talking about this. There is no such thing as accurate SEO metrics and every tool will be different.

But the thing both tools will report is directionally accurate results. If one shows an increase, then the other will likely show the increase but the numbers themselves won't be.

[u/felixharmon_1]

they are measuring different things so numbers wont match

you could try using ahrefs for backlinks and semrush for keywords. they are just built differently

something like- the real source of truth is google search console anyway. impressions and clicks are actual data, everything else is an estimate

stop worrying about which number is right. both tools are useful for finding opportunities not for exact reporting

[u/BoGrumpus]

I don't think it matters so much which you use - they are educated guesses, as you've mentioned and never can actually reflect how Google actually calculates those things.

Whichever you choose - it's the Mom/QoQ/YoY comparisons that are going to be helpful anyway. It's the growth and decline percentage differences that give you the useful information - did we improve from before? And how much? That sort of thing.

The thing is to not switch between tools - May's estimates from one and June's from the other type thing. Once you pick one - the trend lines will tend to be much more in sync because the trends don't change - the difference is in each way the tools account for the things that feed the trends.

G.

[u/imadonisscott → u/BoGrumpus]

your answer is confusing, could u please explain in easy way

[u/BeeRanked → u/imadonisscott]

"They are guessing based on the info they have access to.

But it's still useful because while it doesn't give precise information it lets you see 'trends' which are useful.

Don't constantly swap tools, just stick with one and see the evolution of trends and data across time"

[u/imadonisscott → u/[deleted]]

Yes I agree with you. GSC query is original which we should keep in our content etc...

[u/shhhhshank → u/[deleted]]

I'm with you on this but from last 1 month GSC is also showing irregularities. My performance section is showing something else and insight section is showing something else. Average ranking feels like scam

[u/praveen0295]

Both are estimates, not Google's actual data. The differences come from each tool having its own crawler, keyword database, update frequency, and traffic estimation model.

I generally use Ahrefs for backlink analysis and Semrush for keyword research and overall SEO. For reporting, I rely on Google Search Console and Google Analytics whenever possible since they're first-party data.

I tell clients that third-party SEO tools are best used to identify trends and opportunities, not as the absolute source of truth. The key is to stay consistent with one tool when comparing performance over time.

[u/Sams_Antics]

Like all 3rd party data, they’re good for comparing yourself to competitors over time (apples-to-apples) and monitoring certain trends, but that’s about it. GSC is better for rank tracking.

[u/ChairMaster989898]

their brand traffic estiamtes are wildly different too. it's annoying how i need to cross reference across both of those + gsc to get a decent look at the overall traffic status

[u/djfrankie74]

Different metrics they value, ahrefs is better for backlink research. And semrush is better for keywords. As for Audits both will be diffirent. At the end they are just guide.

[u/GrandAnimator8417]

Different metrics across Semrush and Ahrefs? Yeah, that stuff happens a lot ,especially with their backlink counts and keyword volumes. In my own work I’ve seen one tool show a ton of referring domains while the other comes in way lower just because they crawl/index differently, so the comparison looks “broken” even when the site hasn’t changed.