Is Similarweb Reliable? Not Entirely Accurate But a Good Source [My Findings]

Since the past few days, I have extensively covered Similarweb, be it the website not accessible or different issues. And all that research made me wonder whether Similarweb is really a reliable source of traffic-related information?

Naturally, I checked studies and forums posts by users on the accuracy of Similarweb, in addition to comparing my website’s data on Similarweb and GSC (Google Search Console) and BWM (Bing Webmasters Tool).

I was surprised with the results. A platform so extensively used couldn’t be delivering this level of accuracy!

Is Similarweb reliable and accurate?

Similarweb is not entirely accurate, no matter what researches and studies tell you. It’s traffic-related data often varies by as much as 100-200% when compared to actual visits verified using Google Analytics or GSC.

When I started comparing the data sourced from Similarweb and GSC for three websites, I saw a 70-200% variation. Of course, data from GSC didn’t include the visitors coming via other search engines. So, the visit count from Similarweb is bound to be higher!

But should it be as much as 200%? No, that’s not possible by any logical standards. Here’s my argument:

According to Statcounter’s search engine market report for Feb’25, Google leads the race with over 90% of the market share. Search engines that follow include Bing at 3.95%, Yandex at 2.3%, and Yahoo at 1.3%.

So, even assuming that your website performs better on Bing and Yahoo compared to Google and is ranked higher on the first two, the data shouldn’t be this inaccurate, given Google’s dominance in the market. In most cases, traffic from different search engines is aligned with their market share.

But there’s an interesting aspect with almost every website when you check its traffic using Similarweb. The data usually varies by the same percentage for websites in a given traffic range. Say, for websites that actually get 20-30k visits/month, Similarweb will show 35-60k visits/month.

When you move higher up in terms of traffic, this variation usually increases. For websites with 1-3 million visits, Similarweb usually detects it as 3-6 million.

Here is a table that showcases approximate difference between the traffic data sourced from GSC and Similarweb:

Website	GSC (visits/month)	Similarweb (visits/month)	% Difference
1	72,000	154.52	114.61%
2	543,000	1.23 million	126.51%
3	2.32 million	5.92 million	155.17%

So, we can conclude that data from Similarweb is not very reliable or accurate. You can verify the same for any domain you own or have the data for!

How does Similarweb get its data?

Since we have established the inaccuracy of traffic-related data from Similarweb, it’s important to understand why that is the case. And for that, you must know where Similarweb gets its data from.

According to Similarweb’s official website, this data is sourced from several sources, including these primary ones:

• Data directly shared by websites with Similarweb by connecting their Google Analytics account.
• Data sourced from consumer products that collect visit-related insights.
• Data shared by organizations that have partnered with Similarweb. This includes DNS address providers and ISPs.
• Information gathered from public data sources that are available to everyone. Similarweb, like Google and other search engines, indexes data from websites and apps to share insights into monthly visits.

As you can see, for most websites, Similarweb uses third-party sources to gather information about monthly visits, and as a result, often gets it wrong. However, for websites with Google Analytics connected to Similarweb, the traffic shown is mostly reliable and accurate!

How can I get more accurate traffic data of websites?

A couple of years ago, a study by SparkToro found Similarweb to be the most reliable among popular traffic monitoring tools like Ahrefs, Semrush, and Datos. While this is still the case, it only means one thing. Other similar tools, too, show data that is highly inaccurate. So, what, then, is the best option?

In my opinion, if you own the domain, set up Google Search Console, Bing Webmasters Tool, and Yandex Webmaster. Now, you can simply add the visits from all three to get an accurate estimate of monthly traffic to the website.

Advanced users who want to gain insights into conversion and intend to track user actions and similar stuff must opt for Google Analytics. It will help you do all that and much more while also showing the monthly website traffic.

That’s all for today. You now know whether Similarweb is reliable and accurate and the reasons behind its unreliability. Remember, this doesn’t mean that you let go of it. Use Similarweb but only for rough insights and comparisons. Just don’t blindly trust the data!

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If you have thoughts on Similarweb’s reliability, drop them in the comments section below.