SimilarWeb vs Alexa – Competing on Competitive Intelligence

SimilarWeb and Alexa are two of the biggest players in the online competitive intelligence field. Alexa, one of the most well-known and commonly used competitive intelligence tools around the world, has been the go-to for most marketers, publishers and business executives for years. A company that in its 8 years has rapidly grown, SimilarWeb gives Alexa a good run for its money when it comes to traffic data, web rankings and more.        

As a digital marketing company with many years experience utilizing such tools (and following our full reviews of both Alexa and SimilarWeb), we at Seperia have decided to put these two competitive intelligence powerhouses head to head, to help you decide which is the right tool for your marketing and business decision needs.

For the purpose of this comparison, we have compared SimilarWeb and Alexa using their ‘most popular’ plans- that is, the plans they encourage users to purchase- SimilarWeb’s Advanced vs Alexa’s Insight. We have chosen as our ‘test’ domain.

Site Overview Insights

Whilst SimilarWeb’s Advanced plan allows a more flexible choice of timeframe for the data (up to 12 months), Alexa’s site overview insights are averaged out based on the previous 3 months of data. So for the purpose of the site overview comparison, we have set the data range in SimilarWeb to the past 3 months.  


The site overview data supplied by SimilarWeb is split into two main categories- Website Audience and Traffic Sources.

Audience Overview

The Audience Overview offers a clear layout of metrics such as:

  • Total Visits: non-unique visitors; also includes interactive graph to display average monthly visits, average visit duration, pages per visit and bounce rate.   
  • Website Ranks: Ranks are given for global comparison, country comparison and category comparison.
  • Traffic Per Country: percentages for the top 5 countries sending traffic to  
  • Traffic Sources: percentage breakdown of channels sending traffic to
SimilarWeb Audience Overview

SimilarWeb’s Audience Overview

Global Rank: 13
Traffic from September to November 2015: 3,153,000,000
% of Traffic from the US: 72%
Top 3 Traffic Sources: Direct (42%), Search (26%), Referrals (24%)


Traffic Overview

The Traffic Overview provides a slightly deeper look into a domain’s traffic, offering the following metrics:

  • Traffic Share: same as Traffic Sources in the Audience Overview, this again offers a breakdown of traffic by source.
  • Traffic Volumes by Source: graph showing the monthly traffic volumes from each source.
  • Organic vs. Paid Traffic: compares the percentage of traffic that visited via organic search as opposed to paid search results, for desktop traffic.
SimilarWeb Traffic Overview

SimilarWeb’s Traffic Overview

% Organic Traffic: 98%
Traffic Volume from September to November 2015: Direct (1,325,751,534), Search (820,552,800), Referrals (764,391,789)


How Can I Use This Data?

SimilarWeb offers a clear and concise overview of a domain’s traffic and audience statistics. Within seconds, you can check for trends in traffic, discover a domain’s most popular traffic sources-perhaps find untapped traffic channels for your own site- and check how well/poorly users engage with that site.


Alexa’s site overview offers a comprehensive collection of metrics by which we can analyze a domain. These metrics include:

  • Alexa Traffic Rank: calculated using the average daily visitors and pageviews of a site over the last 3 months, the Alexa rank indicates the popularity of a domain ( in comparison to other domains.
  • Monthly Unique Visitor Metrics: calculated over past 30 days, this data is only available on the advanced plan.
  • Audience Geography: indicated percentage of users that visit from each country.
  • Engagement Metrics: based on the last 3 months, shows bounce rate, daily pageviews per visitor and daily time on site.
  • How do visitors arrive at your site?: includes percentage of traffic from search engines (from both free and paid search results), top keywords (which links to Alexa’s full keyword report) and top 10 upstream sites (sites visited immediately before visiting
  • Where do visitors go next?: top 10 downstream sites (sites immediately visited after  
  • Backlinks: offers the top 5 sites, but links to a full backlinks report.
  • Related Sites: includes sites that receive traffic from the same keywords as, additional sites owned by, sites with similar names and related sites based on industry categories.
  • Where do visitors go on your domain: top subdomains based on monthly visits.
  • Page Load Time & Company Info.
  • Audience Demographics: including gender, education, age, income and more.
Alexa Overview

Alexa’s Site Overview

Global Rank: 6
Traffic in November 2016: Need to upgrade to view traffic data.
% of Traffic from the US: 60.3%
Top 3 Traffic Sources: Only offers statistics for Search: 8.10%


How Can I Use This Data?

Alexa’s Site Overview offers a slightly more descriptive picture of the traffic flow of the domain you are analysing. By analyzing information such as the upstream and downstream sites, visitor demographics and backlinks of a competitor’s domain, you can find new online opportunities for your business, such as potential partner sites, new target markets and much more.    

Additional Metrics

Whilst some might consider SimilarWeb’s Site Overview to be shorter in data and insight compared to Alexa’s, the additional categories of metrics offered by the platform outshine those offered by Alexa. Let’s take a look at some of these key metrics, head to head.

*Note, the date range for both SimilarWeb and Alexa metrics have been set for the past 12 months.

Keywords Insights

SimilarWeb’s ‘Search’

The Search section on SimilarWeb’s platform offers more than just keyword rankings. Here, we are presented with the following information:

  • Total visits: visits to from search engines over the last 12 months. This data is also presented on an interactive graph that shows trends for all search visits, organic search visits and paid search visits.
  • Organic/ Paid: traffic volumes for both organic and paid traffic.
  • All Search Terms: keywords that send both organic and paid traffic to, ranked by the percent of search traffic each keyword sends to the site. This list can be filtered by the type of search traffic, search channels and sources.
  • Popular words within search terms.
  • Search Ads: An actual look at’s paid ads and the keywords for which those ads appear.
SimilarWeb Search

SimilarWeb’s Search Insights

How Can I Use This Data?

The keyword data here can offer you an insight into your competitor’s target keywords, which can in turn assist your keyword targeting strategy. Such insights include: which keywords are they targeting that you aren’t, are their paid campaigns attracting traffic from sources you aren’t yet advertising on, ideas for ad copy and much more.

Alexa’s ‘Site Keywords’

Alexa’s Site Keywords offers 3 categories of keyword information:

  1. Organic Keywords: ranked by the percentage of search traffic each keyword brings to
  2. Paid Keywords: ranked by the number of ads that appear for each keyword.
  3. Opportunities: shows keywords that send traffic to but are also being targeted by the site’s competitors.
Alexa Keywords report

Alexa’s Organic Keywords Report


How Can I Use This Data?

Offering a slightly more basic look at a site’s keywords, Alexa’s insights can help you find new keywords to target for both organic and paid search campaigns as well as check the competitiveness of top keywords.

Referral Websites & Backlinks Insights

SimilarWeb’s ‘Referrals’

In this section, we are presented with data about the sites that refer traffic to and the referal traffic itself, including:

  • Total Visits from Referring Websites
  • Up to 500 of the referring websites (including each website’s category, global rank and traffic share).  
SimilarWeb referrals

SimilarWeb’s Referrals Insights

How Can I Use This Data?

The referrals data is presented clearly and also includes the option to filter results by Website Category, or simply search for a domain to check its share in the referral traffic pie. This information is useful for finding the top sites that are currently sending traffic to yours or your competitor’s sites, allowing you to decide which external sites are the most relevant to build (or strengthen) business and marketing partnerships with.

Alexa’s ‘Sites Linking In’

Here, Alexa offers a list of domains linking to (1,038,956 sites to be exact). The list includes the domain, Global Rank of the domain and the page sending the most traffic from that domain to yours.

Alexa sites linking in

Alexa’s Sites Linking In Report

How Can I Use This Data?

The benefit of Alexa’s links list is that essentially it is a full backlinks report. However, further to this, you are not shown how much traffic (let alone if any traffic) is sent to your chosen domain from these domains. There is also no information on when these links were added and how many links there are per domain. To gain a better analysis of your or your competitor’s backlinks history, we would suggest checking instead of Alexa’s Sites Linking In list.    

Site Comparison

The site comparison features on both Alexa and SimilarWeb are certainly the more interesting and useful features of the two. After all, we are seeking competitive intelligence- so what better way to find it than by comparing your top competitors all at once!

Whilst Alexa’s comparison feature allows the user to insert up to ten domains, SimilarWeb only allows you to add up to five, so for the purpose of this comparison we limited the comparison to 5 domains. To gain a better understanding of’s online competitiveness, we have chosen to compare the site to,, and

SimilarWeb’s ‘Compare’ Feature:

The site comparison feature in SimilarWeb is not only a stand out for the range of insights you gain, but the bright colors and visual presentation of data make it just that little bit more fun to play around with. Whilst analysing your chosen site, you can quickly and simply add the competitors’ domains by clicking the ‘Compare’ button at the top of the page, offering a comprehensive comparison across all of SimilarWeb’s data categories.  

SimilarWeb audience comparison

SimilarWeb’s Audience Overview Comparison of 5 Domains

SimilarWeb traffic comparison

SimilarWeb’s Traffic Comparison of 5 Domains


How Can I Use This Data?

The true beauty of SimilarWeb’s site comparison feature is that you can now compare the additional websites based on the exact same metrics you compared the original website on.  

This means you can go from analyzing one site’s traffic sources, search data, referral traffic, keywords and more, to analyzing those exact same metrics for 5 different domains in a matter of seconds. This could be a real eye opener, if your site is lagging well behind its competitors in certain areas, a rethink of that strategy is needed ASAP!

Alexa’s ‘Site Comparisons’

Alexa’s site comparison feature is a stand alone section, offering a set of metrics by which you can compare up to 10 websites. These include:

  • Historical Traffic Trends & Traffic Metrics: including a comparison of the Alexa rank, reach and Pageviews of the chosen sites.  
  • Monthly Unique Visitors: only available on the Advanced Plan.
  • Engagement Metrics: including Pageviews per user, bounce rate and time on site.
  • Traffic Sources: compare the sites based on the share of search traffic, social traffic, traffic from links and direct traffic that arrive at their site.  
  • Reputation Metrics: including sites linking in, Facebook likes and shares and Google +1’s.
  • Demographics: Alexa compares the demographics of each site’s visitors against the “internet average”, such as: gender, education, location, age, income, ethnicity and children.  
Alexa's Traffic Comparison

Alexa’s Traffic Comparison of 5 Domains

How Can I Use This Data?

The majority of metrics offered in the site comparison are the same as those in the Site Overview section. However, there are some additional metrics that could be of interest, not only for comparison but also to learn more about your site.

The additional metrics such as the traffic source breakdown and reputation metrics offer marketers an additional insight and source for ideas on how to strengthen your site externally.

Alexa traffic comparison

Alexa’s Traffic Sources Comparison

For example, the Reputation Metrics would indicate that has a lot of work to do on its Facebook Page. By taking a look at the Facebook pages of the competitors with the most likes and shares (, and, could probably find some inspiration for methods to encourage more user engagement with their Facebook page.

Alexa reputation metrics

Alexa’s Reputation Metrics Comparison

SimilarWeb’s Mobile Data and Additional Insights

If there is one area where SimilarWeb is an obvious stand out, it is in regards to the mobile data and additional insights offered on their platform. In an age where ‘everything is going mobile’, digital marketers, publishers and all online businesses need to keep track of theirs and their competitors actions in the mobile arena. As we can’t offer a true comparison to Alexa’s features in this case, here is a quick snapshot of some of SimilarWeb’s additional features:

Industry Analysis

Includes total desktop visits, category traffic stats, sub-categories, traffic per country, traffic sources, category leaders and more.

SimilarWeb Industry Analysis

Industry Analysis for the ‘Shopping’ Industry


Mobile App Analysis

Including App Rankings in main and additional categories, Android app engagement, usage patterns and more. The Mobile App Analysis also allows for comparison of up to 5 apps.

SimilarWeb mobile app rank

Mobile App Ranking and Rating


Google Play Keywords

Includes the app’s position in Google Play for the chosen keyword.

Google play keywords

Google Play Keyword Analysis for Keyword: “amazon”

Data Sources and Accuracy


According to SimilarWeb’s website, their data is collected from 4 main sources:

  1. SimilarWeb Panel: With over 200 million monitored devices across over 190 countries, the Panel’s data is collected from tens of thousands of software applications and extensions.
  2. SimilarWeb Crawler: SimilarWeb’s own web crawlers scan over 2 billion web pages per month to analyse online content.
  3. ISP & Partnership Data: Local internet service providers located in different countries help SimilarWeb collect clickstream and app data.
  4. Direct Measurement Learning Set: Hundreds of thousands of websites and apps directly connected to SimilarWeb that provide measurement sources.


SimilarWeb claims their collected data is carefully checked and screened to ensure statistical bias is ignored from their samples. The traffic algorithm calculates visits on a daily basis to ensure the representations are as accurate as possible.

Our team performed a small test, analyzing a number of our clients’ websites in both SimilarWeb and Google Analytics to compare the results. Our tests indicated that SimilarWeb’s traffic data (visits and traffic sources) more closely represented data from Google Analytics for sites with greater sums of traffic (over 50 thousand monthly visits). However, SimilarWeb’s data was quite accurate in terms of reporting traffic trends and distributions no matter the size of the site.   


Alexa’s traffic data is collected from their Traffic Panel, sampling millions of users’ online behavior via one of over 25,000 browser extensions. On top of the extensions, Alexa also pulls data from sites that have installed the Alexa script on their site (and certify their metrics).

We compared Alexa’s data with that of Google Analytics for a number of our clients’ websites. Whilst certain metrics such as pages per session and audience geography were spot on, others were not as accurate. Although, we did notice that for websites with greater traffic, the breakdown of traffic sources (in Alexa’s site comparison) did more closely mimic the results of Google Analytics. Interestingly, for sites with smaller quantities of traffic (in the range of 60,000-70,000 visitors per month) for which it had ranked the site out of its top 100,000, Alexa could not offer any data insights, while SimilarWeb offered a full analysis.      

Another thing to note, is that the majority of Alexa’s insights are based on the previous 3 months of data collection, whilst SimilarWeb allows you to change the data set to analyse metrics from 1 month to 12 months prior.  

Packages and Pricing

Alexa and SimilarWeb both offer 3 paid packages, as well as a sneak peak of their data for free. Without signing up, you can view the basic Site Overview data on Alexa or a comprehensive selection of metrics on SimilarWeb (such as traffic sources, top 5 paid and organic keywords, similar sites and related mobile apps).  

SimilarWeb’s Plans

  • Basic ($199/month): Offers website analysis with up to 6 months of data, 30 results per metric and full website comparison. Also includes Mobile App Analysis with 3 months of ranking and 6 months of traffic data.
  • Advanced: Offers website analysis with up to 12 months of data, 500 results per metric, full website comparison and mobile app analysis. The Advanced package also includes Industry Analysis (traffic and engagement metrics for over 200 industry categories) and Google Play Keywords insights.
  • Enterprise: Website analysis with up to 24 months of data, unlimited results, filtering by countries and US states, mobile web metrics, full mobile app and industry analyses and Google Play Keyword Insights. The Enterprise package also offers Mobile App Engagement data such as daily active users, usage patterns, retention, app index, current installs and 6 months of engagement data. This mobile app data is a definite bonus as the online shift to mobile continues.

Alexa’s Plans

  • Basic ($9.99/month): includes Alexa Rank, engagement metrics, reputation metrics, basic demographics and up to 6 months of historic traffic trends (reach% and pageviews%).
  • Insight ($49/month): offers the same metrics as the basic plan plus traffic sources, full audience demographics and keyword research.
  • Advanced ($149/month): offers the same metrics as the Insight plan plus Alexa’s Site Screener, full traffic metrics plus a full site audit every two weeks from Alexa.

Alexa currently offers a 1 week free trial on all plans.

So, SimilarWeb or Alexa?

Whilst it is clear the Alexa plans are a lot more budget-friendly, one can not ignore the amount of features and additional data SimilarWeb offers, especially when it comes down to mobile web data.        

The user experience on Alexa is simple and clear, but SimilarWeb’s platform feels more intuitive, is more interactive and is presented in a very visual way making the data easier to understand as well as share with other key decision makers.   

If you are seeking a quick overview of yours or your competitor’s online traffic, user demographics and overall popularity, Alexa will satisfy your competitive intelligence needs. For the discerning digital marketer or business professional seeking concrete competitive insight for marketing strategy and decision making, SimilarWeb may just be your best choice.   

Contact Us to Find out More