Why Are Rankings Different on SEMrush Than Ahrefs?

If you’ve ever pulled up keyword ranking data for the same website in both SEMrush and Ahrefs and felt like you were looking at two completely different websites, you’re not imagining things. The discrepancy is real, it’s common, and it trips up both beginners and experienced SEOs who don’t understand what’s actually happening under the hood of each tool.

I’ve been working with both platforms for years across hundreds of client projects, and I can tell you with confidence: neither tool is wrong, exactly. They’re just measuring different things, at different times, using fundamentally different methodologies. Once you understand why those gaps exist, you stop panicking about the discrepancies and start using both tools more intelligently.

Let me break this down in full detail.

Why SEMrush and Ahrefs Show Different Rankings

SEMrush and Ahrefs show different keyword rankings because they use separate crawler infrastructures, independent keyword databases, different data collection frequencies, and distinct methodologies for estimating search positions. Neither pulls live data directly from Google. Both are making informed estimates from their own proprietary data sets, which will naturally produce different results for the same domain and keyword.

They’re Not Reading Google’s Mind – They’re Making Educated Estimates

This is the most important thing to understand, and I wish more people led with it. SEMrush and Ahrefs do not have access to Google’s actual ranking data. Google doesn’t share that. What these tools do is crawl the web independently, simulate searches from various geographic locations and devices, and then catalog what URLs appear in those simulated SERPs.

Think of it this way: both tools are standing outside Google’s house, peering through different windows at different times of day. They’re both trying to describe what they see inside, but their vantage points are different, and Google keeps rearranging the furniture.

Every position estimate you see in SEMrush or Ahrefs is a snapshot derived from third-party data collection. It is not a ground truth. It is a signal. Treating it as anything more precise than that is the first mistake.

The Core Reasons Rankings Differ Between SEMrush and Ahrefs

1. Different Keyword Databases

SEMrush and Ahrefs maintain completely separate keyword databases built independently over time. SEMrush claims one of the largest keyword databases in the industry, with billions of keywords across multiple countries. Ahrefs has its own massive keyword index built from its own crawler infrastructure and clickstream data.

The practical consequence: one tool may have a specific keyword in its database that the other doesn’t, or one tool may have more historical data points for a particular keyword. If Ahrefs doesn’t register a keyword at all in your niche, it won’t report a ranking for it. SEMrush might catch it, and vice versa.

This alone explains a significant portion of “missing” keywords when you compare reports side by side.

2. Different Crawl Frequencies and Update Cycles

Ahrefs and SEMrush do not crawl or refresh their data on the same schedule. Depending on the keyword’s volume and competition level, each tool may check ranking positions with different frequency. High-volume, competitive keywords get refreshed more often. Long-tail, lower-volume keywords may only be checked every few weeks.

If SEMrush crawled a keyword yesterday and Ahrefs crawled it last week, and Google had a ranking shuffle in between, you’re looking at data from two different points in time. Rankings fluctuate constantly – Google makes thousands of algorithm adjustments annually – so a one-week gap in data collection can produce noticeably different position numbers.

3. Geographic and Device Variation in Data Collection

Both platforms simulate searches from different locations and on different device types to build their datasets. The challenge is that their proxy networks and data collection infrastructure don’t overlap. SEMrush might be checking rankings from IP addresses in one set of cities; Ahrefs might be checking from another. Since Google serves personalized and localized results, even small geographic differences in where the “simulated search” originates can produce different position data.

Device type matters too. Desktop and mobile rankings in Google are not identical. If one tool weights mobile data differently than the other, that’s another source of divergence.

4. Clickstream Data vs. Pure Crawler Data

This is a nuance that very few articles talk about. Ahrefs heavily relies on its own web crawler (AhrefsBot, one of the most active bots on the internet) to gather backlink and ranking data. SEMrush incorporates clickstream data as part of its methodology, which means it uses anonymized behavioral signals from actual users browsing the web to inform its keyword and traffic estimates.

These are fundamentally different measurement approaches. Crawler-based data is more direct but limited by what the crawler actually visits. Clickstream data can capture organic traffic signals that a crawler might miss, but it introduces its own biases depending on the user panel involved. The result is that the two tools are, in some sense, measuring slightly different things even when they’re reporting on the same keyword.

5. SERP Feature Detection Differences

Modern SERPs are cluttered with featured snippets, local packs, image carousels, video results, People Also Ask boxes, and AI Overviews. What counts as “position 1” is not always obvious. A URL might appear in a featured snippet and also in the organic results below it. Some tools count the snippet as a separate position, others fold it into the organic ranking. SEMrush and Ahrefs handle SERP feature classification differently, which can cause what appears to be a ranking discrepancy when it’s really just a definitional difference.

6. Index Size and Keyword Discovery Methods

Each platform discovers keywords through different means. Ahrefs discovers keywords primarily through its massive web crawl – when it sees pages ranking, it catalogs the terms those pages appear for. SEMrush discovers keywords through a combination of crawling and clickstream signals. The result is that each tool’s keyword discovery process favors different segments of the search landscape. Niche, technical, or very low-volume queries may be captured by one and completely missed by the other.

How Big Are the Discrepancies, Really?

Based on my experience auditing sites across competitive industries, the ranking data between SEMrush and Ahrefs tends to broadly agree on high-volume head terms where both tools invest the most data collection resources. For keywords with 10,000+ monthly searches in competitive niches, you’ll typically see position estimates within a few spots of each other.

Where you see significant divergence:

• Long-tail keywords (under 500 monthly searches) – one tool may not track them at all
• Local SEO keywords with geo-modifiers – geographic data collection differences amplify the gap
• Fresh content that has recently moved in rankings – update latency creates timing gaps
• Volatile SERPs in fast-moving industries – any delay in crawling captures a different ranking reality
• SERP feature-heavy queries – definitional differences around snippets and packs create apparent discrepancies

The Myth That One Tool Is More Accurate Than the Other

I hear this constantly – “Is SEMrush more accurate than Ahrefs?” or “Which tool should I trust?” And honestly, this framing misses the point. Asking which is more accurate assumes there’s a fixed ground truth that one tool is closer to. But since Google rankings fluctuate by the hour for many keywords, and neither tool is checking positions in real-time, “accuracy” is almost the wrong concept to apply here.

What you should be asking is: which tool is more useful for your specific purpose?

• For backlink analysis, Ahrefs has historically been regarded as having a more comprehensive and fresher link index
• For keyword research breadth and competitive intelligence, SEMrush’s clickstream-informed data often surfaces keyword opportunities that pure crawlers miss
• For rank tracking over time, both platforms have dedicated rank trackers that you can configure for specific keywords, locations, and devices – which is more reliable than their organic keyword databases for monitoring specific positions

The organic keyword databases in both tools are research tools, not precision ranking instruments. If you need precise rank tracking, use the dedicated rank tracker function in either platform, or use a purpose-built tool like AccuRanker or STAT. Those tools check specific keyword positions on demand, which is a different and more reliable methodology than the organic keyword database approach.

Why Your Google Search Console Data Won’t Match Either Tool

Here’s where things get even more interesting. You might compare SEMrush and Ahrefs against Google Search Console and find that GSC tells yet another story. Search Console shows your actual average position across all the searches where your site appeared – including personalized results, logged-in Google users, searches from all devices, and every geographic variation. It’s real data from Google’s own servers, but it’s also an average across enormous variability.

SEMrush and Ahrefs are making one-time position snapshots from simulated, non-personalized searches in specific locations. GSC is giving you an average of millions of real, personalized, variable impressions. They will never match, and they shouldn’t be expected to. Each data source is measuring a different thing and is useful for different purposes.

“Google Search Console tells you what happened. SEMrush and Ahrefs help you understand why and what to do next. Trying to reconcile all three into one ‘accurate’ number is a category error that wastes time and creates unnecessary confusion.”

What This Means for Your SEO Strategy

Understanding why rankings differ between SEMrush and Ahrefs isn’t just academic. It has direct practical implications for how you run SEO campaigns.

Don’t Build Client Reports Around One Tool’s Position Data

If you’re reporting rankings to clients based on organic keyword database data from either tool, you’re presenting estimates as facts. A better approach: use the dedicated rank tracker function, configured for your client’s actual target location and device type, for a specific list of agreed-upon keywords. That’s a repeatable, apples-to-apples measurement. The organic keyword database is for research, not for ongoing performance reporting.

Use Divergence as a Research Signal

When SEMrush shows you ranking for a keyword that Ahrefs doesn’t – or vice versa – don’t dismiss the discrepancy. Sometimes the keyword that only one tool captures represents a genuine opportunity the other platform’s database hasn’t fully indexed yet. Cross-referencing both tools’ keyword data often uncovers the fullest picture of what you’re actually competing for.

Weight Your Tool Selection by Task Type

My practical workflow: I use Ahrefs when I want to dig deep into backlink profiles, understand content gap opportunities through their Content Gap tool, and research topic clusters based on what’s actually earning links. I use SEMrush when I want broader keyword discovery, competitive advertising intelligence, and technical site audit data. For rank tracking I use dedicated tracking tools or GSC as the primary source of truth.

Stop Worrying About Small Positional Differences

If SEMrush says you’re at position 4 and Ahrefs says position 7 for the same keyword, this is not a problem to solve. Both tools are capturing a window of time and a simulated geography. The real-world ranking at this moment, across all users and locations, is probably somewhere in that range – possibly different from both. What matters is the trend direction over time, not the exact position on any given day.

Common Mistakes SEOs Make When Comparing Tool Data

• Treating organic keyword position data as live rankings. It’s not. It’s a historical estimate from a simulated crawl.
• Reporting keyword counts as a performance metric. The number of keywords a site “ranks for” in SEMrush vs Ahrefs will always differ because of database differences. It’s not a meaningful comparison.
• Comparing traffic estimates between platforms. Organic traffic estimates diverge even more than position data because they compound two estimates: position accuracy and click-through rate modeling. Neither tool’s traffic estimate should be cited as authoritative in client-facing reporting.
• Ignoring the importance of rank tracker setup. Most SEOs have access to rank tracking functionality within these platforms but underuse it, relying instead on the organic keyword database for ranking information. Set up proper rank tracking for your target keywords and you’ll have far more reliable data.
• Assuming discrepancy means error. A gap between tools almost never means one is broken. It almost always means they’re measuring from different vantage points.

Expert Tips for Getting the Most Out of Both Platforms

1. Always configure location-specific rank tracking in both tools for your most important keywords. Don’t rely on organic keyword database positions for anything you need to track over time.
2. Use both tools’ keyword databases together for keyword research – export from both and consolidate. You’ll regularly find keywords in one that the other misses entirely, especially in niche markets.
3. Cross-reference with Google Search Console for any keyword where you need to understand actual search behavior. GSC’s data is imperfect but it’s real Google data, not third-party estimation.
4. Pay attention to trend direction, not exact positions. If both tools show a keyword trending upward over 90 days, that’s a reliable signal even if they disagree on the exact position today.
5. Use Ahrefs’ rank tracker for backlink-sensitive keyword movements where you want to correlate position changes with link acquisition. The integrated data is useful for connecting the dots between link building activity and ranking response.

Frequently Asked Questions

Why does SEMrush show more keywords than Ahrefs for my website?

SEMrush incorporates clickstream data into its keyword discovery methodology, which can surface queries that a pure web crawler might miss. Additionally, the two platforms maintain independently built keyword databases with different coverage. SEMrush having more total keywords for a domain doesn’t necessarily mean those rankings are more accurate – it often reflects database coverage differences rather than actual ranking gaps.

Which is more accurate for rank tracking – SEMrush or Ahrefs?

Neither organic keyword database in SEMrush or Ahrefs is designed for precision real-time rank tracking. Both tools offer dedicated rank trackers that are significantly more accurate for monitoring specific keyword positions. For highest accuracy, configure a rank tracker in either platform (or use a purpose-built tool) for your specific target keywords, location, and device type. Organic keyword database positions are research estimates, not live rankings.

Can I trust SEMrush and Ahrefs ranking data for client reporting?

You should not use organic keyword database data from either tool as the basis for client ranking reports. The data represents historical estimates from simulated searches and will not match real-world positions with precision. Use the dedicated rank tracking features within each platform, configured for the client’s specific target location, device preference, and keyword list. That produces repeatable, comparable data appropriate for performance reporting.

Why does a keyword show position 3 in SEMrush but position 8 in Ahrefs?

This discrepancy is caused by a combination of factors: different crawl timing (the tools checked this SERP at different times and Google shuffled rankings in between), different geographic simulation points for the search query, different SERP feature classification systems (affecting what counts as “position 1”), and potential differences in how each tool’s algorithms estimate positions when data is sparse. For high-volume competitive keywords, both numbers are reasonable estimates. For niche or volatile keywords, larger gaps are common.

Does Google Search Console show the same rankings as SEMrush and Ahrefs?

No, and it shouldn’t be expected to. Google Search Console reports average position across all real impressions – including personalized results, all devices, all geographies, and all logged-in users – which are inherently variable. SEMrush and Ahrefs report snapshots from specific simulated non-personalized searches at specific times and locations. The three data sources measure different things and will consistently disagree. GSC is real behavioral data from Google’s servers; SEMrush and Ahrefs are third-party research estimates. Each serves a different analytical purpose.

The Bottom Line

Ranking discrepancies between SEMrush and Ahrefs are not bugs. They’re not evidence of one tool failing or deceiving you. They’re the natural result of two independent companies building separate data infrastructure to approximate something that Google doesn’t share publicly.

The professionals who get the most value from these tools are the ones who understand their methodological limitations and use each platform for what it does best. Stop trying to reconcile the numbers. Start using the data strategically.

If you’re spending time arguing with yourself about whether your site “really” ranks at position 4 or position 7, you’re missing the point. The real SEO work – building authority, earning links, improving content, solving technical issues – moves rankings in ways both tools will eventually agree on.

If you want help interpreting what your SEMrush and Ahrefs data is actually telling you – and building an SEO strategy around the real signals rather than the noise – I work with businesses at AffordableSEOExpert.com to do exactly that. Reach out and let’s look at your data together.