What is the best free tool to analyze the SEO

What is the best free tool to analyze the SEO and traffic of a website? Is it Semrush or SimilarWeb?

To answer this question, I made a comparison between these two solutions, with the advantages and disadvantages of each.

In order to make it simple and accessible to everyone, I used the free versions of the 2 tools.

This will allow you to have an opinion on Semrush and Similarweb for “general public” use, even if you do not have a large budget to invest.

Indeed, what is interesting with these two tools is that they offer Freemium offers.

In this file we will therefore see:

  • What these 2 solutions offer in the free version,
  • The relevance of their results, taking Conseilsmarketing.com as an example,
  • The strengths and weaknesses of each tool, with my opinion on Semrush & Similarweb
  • The interest of switching to paid versions of this software.

Clarification: I have been a fan of Semrush for 10 years, and I participate in their affiliate program.

Part 1 – Test the results with your own website


Before starting, I invite you to check the results for your website with the two tools.

To test your site on SimilarWeb 

To analyze your site with Semrush,

Here’s how to use these two tools:

1 – Analysis of website traffic with Similar Web


Once on SimilarWeb.com , all you have to do is type your domain name into the search engine:

You then have a summary sheet with

  • Estimation of your traffic
  • The French ranking
  • The evolution of traffic
  • The main countries of visitors
  • The main sources of traffic (SEO, email, etc.)
  • The top 5 traffic-generating keywords
  • Traffic from social networks (Twitter, Linkedin, etc.)
  • Visitors’ interests
  • The main competing sites

SimilarWeb offers a free version of a synthetic vision of a website, by estimating both Google traffic, but also traffic from social networks, emailings, direct traffic, etc.

It is therefore a 360° vision of a website.

2 – Analysis of your website with Semrush


Just go to Semrush.com , then select France, and type in its domain name:

And you then get a complete analysis of your website (or that of your competitors):

You have access:

  • Your authority score (your influencer level)
  • Your Ranking in France
  • Estimating your traffic from Google
  • The number of referenced keywords
  • Breakdown by country
  • Backlinks
  • Google Adsense ads displayed
  • Traffic by Country
  • The evolution of traffic over 1 month, 6 months, 1 year and for life
  • The display type in Google
  • The evolution of the number of referenced keywords
  • The keywords generating the most traffic
  • The distribution (position 1 to 3…)
  • Top competitors and their traffic, and common/different keywords
  • Referenced pages


Simply put, Semrush lets you see your site the way Google sees it.

It is therefore an analysis of your referencing on Google, with your strengths and weaknesses, with its evolution over time.

Part 2 – Detailed analysis of Semrush and SimilarWeb results for ConseilsMarketing.com

In order to measure the relevance of the statistics of Semrush and SimilarWeb, I simply compared their data and those of Google Analytics.

This provides a reliable basis for comparison on key indicators such as traffic, competitors, etc.

Below are the detailed results.

1 – Analyze website traffic with Semrush or SimilarWeb


My mini benchmark shows that SimilarWeb makes it possible to analyze the traffic of a website, all channels included (Google, social networks, etc.).

This is useful to have a more complete estimate of the traffic generated.

However, in the free version, it is less complete in analyzing traffic via Google than Semrush.

We can see, for example, that it does not take into account changes in Google’s traffic (changes in positioning, Google sanctions, etc.).

Semrush is a little more precise (while far from perfect!) in terms of visitors from Google, with the added benefit of good visibility of the traffic generated by Google Ads.


  • The official statistics of my Google Analytics account

Here are the visitor statistics from Google (excluding traffic from other sources, such as emails, social networks, etc.).

My traffic from Google for April was around 149,000 visits.

This figure will be the basis for comparisons with Semrush, since Semrush only takes into account traffic from Google.

If this time I take all the channels, i.e. the baseline of this SimilarWeb, I have in April 2021 a total of 188,617 visitors.

  • Similarweb statistics (Google and other channels)

Estimated traffic for April 2021 is 210,000 visitors versus 189,000 in my Google Analytics (all sources)

The difference is therefore 11% overestimated, which is a good estimate.

At the trend level, we can see that Similarweb still indicates growth in May, while it is wrong, my traffic dropped at the end of May.

SimilarWeb therefore did not anticipate the real decline observed by Google Analytics, and still credits me with an increase in traffic even though this is no longer the case.

For SimilarWeb, my traffic is generated by:

    • 74% through Google
    • 23% direct traffic (we type my URL)
    • 2.87% through social networks
    • 0.4 by emailing

My real statistics via Google Analytics are quite close, with nevertheless poor management of social networks, Google…

  • 75.5% by Google + 3% Bing + 1% ecosia + 0.5 Qwant + 0.3 Yahoo, i.e. 82.94 (74% according to similarweb)
  • 13% direct (23% according to similarweb)


In terms of traffic from social networks, Similarweb is more or less close to real traffic, with an estimate of the source traffic number (Pinterest) and number 2 (Twitter), but the following figures and networks are however less good estimated.



  • Sem rush statistics


Semrush estimates my traffic from Google in April at around 100,000 to 120,000 visitors (with variations in the month) against 149,000 according to my Google Analytics.

There is therefore a difference of 29,000 visitors, which is around 20% less than the reality.

My traffic is therefore underestimated in a more important way than with Similarweb.

On the other hand, the downward trend in traffic is clearly visible on the Semrush curve

Semrush therefore has a better view of the evolution of traffic coming from a website, but with a poorer estimate.

Semrush also sees that I spend almost nothing on Adwords (even if in fact I spend a few tens of euros / day on Google Adwords, but it’s actually negligible).

Semrush’s vision of advertising expenditure is therefore correct.

Here are the statistics of another site that spends a lot on Google Ads, and this trend is immediately visible on Semrush:

The site’s overall traffic is well represented, with the real overall traffic trend (decline in traffic following a change in the site’s CMS, poorly anticipated by the web agency).

On the other hand, what is interesting to note is the orange curve which represents Google Ads traffic.

This curve clearly shows the real increase in traffic linked to Google Ads.

2 – The time spent on the site

In the free version Similarweb offers an estimate that is relatively close to reality.

  • Real stats from Google Analytics (all traffic sources)

The actual duration of a visit is 0.57 seconds, for 1.21 page views.


  • Estimate via SimilarWeb

SimilarWeb estimates visit duration at 1.24 minutes (versus 0.57, or 25% more) and 1.61 (versus 1.21, or 33% more).

There is therefore an over-estimate, but the figure is still significant.

3 – The keywords generating traffic on the site



Whether Semrush or SimilarWeb, the keywords generating the most traffic are not perfect (their top 5 is different from my real top 5).

On the other hand, Semrush is more precise in detecting my “top keyword” (ex: network marketing), while Similarweb shows me keywords that generate less traffic.

Similarly Semrush, even in the free version, offers a much more precise analysis (eg the number of keywords in the first 3 positions in Google and their evolution over time, keywords generating traffic from competitors, etc.).

  • The actual traffic generated by the main keywords via the Google Search Console

The Google Search Console provides a relatively reliable idea of ​​the keywords that have generated the most traffic over the past 6 months.

The keywords generating the most traffic are 2021 resolutions, network marketing, graphic charter, entrepreneurship, SVG file, disposable email, sales funnel and network marketing.


  • The most traffic-generating keywords according to Similarweb

Similarweb identifies only 3,838 traffic-generating keywords.

With first “Disposable Email” / “Personal Branding” / Graphic charter” / “SVG file” / “Temporary email”

We can see that Similar Web has integrated in its top 5 only 1 real keywords (graphic charter), if we extract the synonyms this makes it possible to integrate 2 more keywords (disposable email and SVG file), i.e. 3 /5.

We are therefore on a less reliable estimate, and less precise than reality.


  • Keywords identified by SEmrush


Semrush in the Freemium version is much more complete (more identified keywords, position in Google…), with an analysis of the keyword positioning trend.

The top keywords are also more precise, with Network Marketing, disposable email, entrepreneurship.

If we click on the detailed results, we find Network Marketing, disposable email, entrepreneurship. We are also at 3 / 5 compared to the Google Console, but with better precision on synonyms.

Semrush also detects low-generating expressions, for example MVP which makes 0.25% of my real traffic via Google analytics, while Semrush credits me with 2.26%

Semrush is therefore more precise, even if it forgets strategic keywords, or if it adds keywords that ultimately generate little traffic.

4 – Analysis of the competition


Semrush and SimilarWeb both offer a list of competitors to identify potential keywords, backlinks…

Regarding the list, Similarweb offers a smaller but more precise list.

On the other hand, Semrush offers much more useful and precise information than simple traffic and a top 5 keywords (and to refer to the summary sheet like Similarweb.)

Indeed Semrush allows to see the common keywords and the total number of keywords referenced, the top URLS, the backlinks… which is very important during an SEO audit.

  • SEmrush competitor analysis

Semrush’s analysis is much more comprehensive, with the weight of each competitor, as well as common keywords and the top 100 competitor keywords.

The top 5 competitors listed are:

  • Poignant
  • Creads
  • Webmarketing-com.com
  • Hubspot.com
  • Shopify

This list is not perfect, because Creads, Shopify and Hubspot are rather big sites outside of my B2B theme and personal blogs.

If we expand to the top 10:

  • Poignant
  • Creads
  • Webmarketing-com.com
  • Hubspot.com
  • Shopify
  • leptidigital
  • anthedesign
  • neocamino
  • dynamic-mag
  • Ludosln

This lite is a little more complete, but again with news sites with high traffic.

Nevertheless, it is interesting to see the common keywords, the traffic estimation…

So in the end, this list is both more relevant with smaller sites strongly related to my theme (ex: profinfluent).


  • Similarweb and competitive analysis.

SimilarWeb gives a quite different list from Semrush, with only 2 sites in common, WebMarketing-com.com and Ludsln.

  • WebMarketing-com.com
  • eMarketing.fr
  • Mathieu-tranvan.fr
  • 1min30
  • Redacteur.com
  • Daniloduchesnes
  • Ludosln
  • Blogergosum
  • Marketing terms
  • easyware

This list is a little different, but a little more relevant, with more “small” blogs (with less traffic) and a B2B orientation.


5 – Compare the sites of your competitors



As indicated above, it’s good to have a list of competitor sites, but you have to be able to use this information.

Again, Similarweb remains really on the surface (ranking comparison, top keywords, etc.), while Semrush offers a real SEO audit.

  • Similarweb

The similar web analysis is very light, and focuses on traffic and ranking.

This allows you to measure yourself and see who is the most influential, but without really going into detail (you have to go to each site to see the top keywords).


  • Semrush

The analysis is very complete, as for a traditional site.

You can identify the pages with the most traffic, the keywords that generate the most visits, the evolution of traffic over 1 month, 6 months, 1 year, 2 years and since the beginning.


6 – Analysis of Google Ads advertisements


SimilarWeb again offers a macro view, without going into details.


  • SimilarWeb offers an analysis of the top 5 keywords

This remains very limited, even if the information is interesting to know.

  • Semrush offers finer analysis

Semrush makes it possible to have a very precise estimate of the volume of research, the CPC, the traffic generated… which is much more exploitable.


7 – Chrome extensions

In addition to the tools available on their website, both solutions offer Chrome extensions.

These extensions will be of little interest for daily use, because they only allow you to have traffic statistics, and not estimates of volumes of keywords for a search.

  • SimilarWeb

SimilarWeb offers a very simple chrome extension  , which allows you to display an estimate of traffic for a website via a synthetic identity card (similar to the search on the site).

  • Semrush SEO Quake

SEO Quake is more complete because it allows you to have a macro analysis (and limited to data from the Freemium version) of a website (traffic estimate, backlinks, etc.).

It also allows you to have information such as the density of a keyword on a page… in order to do a mini audit.

For example in this article on Linkedin hashtags , I have an optimization of this keyword.

Note: this kind of information is less useful if you analyze your own website, indeed optimization advice is already offered by the wordpress Rank Math SEO or Yoast SEO extensions.

On the other hand, we regret the fact of not having an estimate of the traffic for a given expression typed in Google.

In fact, the statistical aspect is limited if you are not a professional SEO.

My opinion on Semrush and Similarweb: strengths and weaknesses!

In the end, what is the best free solution to analyze the traffic of a website?

First of all, it should be noted that SimilarWeb and Semrush work differently:

  • Similarweb aggregates data from different sources to estimate overall traffic
  • Semrush uses Google data from keywords to estimate traffic.

SimilarWeb offers the best overall estimate of website traffic.

However, for me, it is clearly Semrush which is the best tool.

Because Semrush is a tool that will allow you to set up an action plan, while SimilarWeb will give you only a macro estimate of traffic, keywords…

Because what matters is what can be done with the data displayed, in particular the performance in natural referencing as well as advertising with Google Ads.

This is where the uses are different:

  • Similarweb will give you a macro vision of the traffic of a website (especially large sites), in order to check the potential of a site (eg to buy it back, to buy a link, etc.). This tool is useful for comparing two sites, but it is not at all useful operationally (not enough detail).
  • Semrush will give you a detailed analysis of natural referencing and Google Ads ads (eg to improve SEO, to identify keywords and backlinks, etc.). You will obtain key points to exploit thanks to the dashboards, and you will easily define an action plan. Likewise, the SEMrush database is larger, which allows you to have data from small French sites / blogs.

That being said, here is a comparison of the advantages and disadvantages of the two tools


  • Semrush

    • Traffic Audit
      • A super complete software (sometimes even too much so there are functions)
      • A better estimate of traffic for small sites (ex: a small blog…)
    • SEO traffic analysis
      • Analysis over 1 month, 3 months, 6 months, 1 year and permanent, which allows to see the evolution over time.
      • The addition of external events (eg changes in the Google algorithm to know the external factors).
      • The list of Backlinks, very important to improve your SEO.
      • The export in CSV format of the data to copy and paste them in the youtube keywords, in WordPress…$
      • The keyword suggestion tool is very accurate and handy (even with limited results).
    • Keywords

      • The analysis of much more precise keywords (questions, alternative keywords, etc.) with a volume for each.
      • More keywords displayed
    • Competitor analysis
      • This is one of the big strengths of Semrush, even in the free version you can get some good keyword ideas.
    • Google Ads budget analysis
      • This is a real plus, very important to know the marketing strategy of your competitors.
    • Free Version
      • The free version is a “freemium” version which allows the analysis of 3 to 4 websites or expressions per day, with a limitation to the first 10 traffic-generating keywords.
      • The possibility of subscribing only for 1 month to the paid version, which allows an SME to benefit from all the power of the tool.
      • The Semrush blog, the web conferences… are really very useful and will allow you to progress, both on the tool, but also on marketing strategies.
  • SimilarWeb

    • Traffic analysis
      • Very (too?) simple with a macro vision
      • Taking into account global traffic analysis (SEO + other channels, including social networks) is really interesting if you want to have a complete idea of ​​traffic, outside of SEO.
      • The best quality of traffic estimation
      • Reading time and page views to check the richness of a site’s content
      • The API for querying data which is richer than that of Semrush
      • The possibility of connecting Google Analytics to Similarweb to compare the real traffic of its site
    • Free Version
      • The free version allows you to have a macro analysis of a website (traffic, top 5 keywords, etc.), but in the end it does not allow you to go further than to estimate the potential of a competitor or a partner. It is therefore a tool to be reserved for large companies, SEO consultants, Agencies… who want a macro vision without really going into the details and setting up an action plan.

The lessers

  • Semrush
    • The price of the paid version ($119.95/month for 5 projects, 500 tracked keywords/project)
    • After some research in the free version, you have to switch to the paid version.
    • SEO Quake which is an extension that only gives SEO statistics (with an overprint of the statistics which sometimes makes it difficult to read). It really loses its appeal because it doesn’t give the keyword volumes on Google searches.
    • Social Media analysis tools, keyword positioning monitoring, unlimited keywords, alerts… are only available in the paid version.
    • A very complete suite, which may lose new users and computer beginners a little
  • Similarweb
    • The price (between $199 to $799 / month)
    • The small sites are not referenced at all (ex: my site Comparatif-CRM.com has no statistics whereas Semrush offers data).
    • The statistics too limited in the free version.
    • The very simple chrome extension, which only allows to analyze the traffic of a website.
    • An analysis only over 6 months, with incorrect trends.
    • Only a very macro vision without ever going into details.

Why switch to paid versions?

Personally, I have never used the paid version of SimilarWeb.

The free version being largely sufficient for my need which is to have an idea of ​​the macro traffic of a website.

On the other hand, I regularly pay subscriptions to Semrush (even if only for a month).

The paid version allows me to do an SEO audit of a complete website,

In this, Semrush will allow you to manage your marketing strategy.

Similarly, thanks to the notion of “project”, I have a vision of the evolution of my website traffic (loss or improvement of positions in google):

This allows you to be alerted if you need to take an action (eg improve an article, share it on social networks, create a new article, etc.) to go up in the results.

Note: the paid version of SimilarWeb also offers this kind of alterting.

What I recommend  , to test the tool without any risk.

Indeed, if you ask support for termination, even on the 6th day, you will not be charged.

So it’s a great way to see for yourself the quality of Semrush…


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