As part of the interview process for Drupal Career Online, we provide potential students with some background information about Drupal so that they can make a more informed decision about whether or not the program suits them. One of the things we communicate is the scope of the Drupal project and its pervasiveness in the web development industry.

As anyone who has tried to find reliable numbers to answer the "how popular is Drupal?" question knows, finding reliable data is often a difficult process. While working to update our recruitment materials this year, we thought we'd share the data we found and the conclusions we've made.

W3Techs

To answer this question, in the past we have relied on the W3Techs (Web Technology Surveys) - a subsidiary of Q-Success, an Austria-based organization. Their methodology seems sound (they monitor the top 10 million web sites), but as their disclaimer states, "This information may be incomplete and inaccurate due to the vastness and complexity of the matter in hand"

As of January, 2021, they report that about 1.5% of all websites they monitor are Drupal-based. This is 2.4% of all web sites using a content management system.

W3Techs does provide a breakdown of usage among the top 1 million, 100,000, etc… sites, but only as part of one of their products (999 €). 

W3Techs reports that Drupal 7 is used by 66.4% of all the websites who use Drupal.

So, how do these numbers compare with other data sources?

Built With

Built With is an Australian company that provides lead generation lists in addition to web development trends among a plethora of technologies. 

They currently report that ~618,000 sites are using Drupal, which equates to 0.97% of all web sites. This is 4th among content management systems after WordPress, WooCommerce Checkout, and Joomla. Their sample size is over 35 million sites.

Their data for the top 1 million sites has Drupal with a 3.28% content management system market share (3rd place), 7.73% in the top 100,000 sites (2nd place), and 12.56% in the top 10,000 sites (2nd place).

Built With also reports that of the ~618k site running Drupal, the United States is responsible for ~250k, with Russia next on the list with ~41k sites.

SimilarTech

SimilarTech appears to be primarily a lead-generation company with offices in Israel and the United States. They state that their "proprietary technology scans more than 30 billion web pages per month."

For Drupal, they report that ~236,000 unique domains run Drupal, which equates to ~337,000 sites (I'm assuming that subdomains account for the significant difference in these numbers). 

One potential major problem with their reports is that they often separate Drupal into multiple categories, including "Drupal", "Drupal 7", and "Drupal 8".

While they report that Drupal is used on 0.483% of all sites, it is not clear if this refers to just their "Drupal" category or includes their "Drupal", "Drupal 7", and "Drupal 8" categories. They appear to also break up other content management systems in a similar manner, making it difficult to draw reliable conclusions.

In their list of the top 1 million sites, they report that "Drupal" is used on 2.55% and "Drupal 8" on 0.81% (they only provide the top 8 positions). 

SimilarTech reports that after the United States, Russian sites account for the most Drupal sites with ~32,000. 

Analysis

So, which data can we trust? What is the real answer? As you might imagine, it is difficult to say…

Removing the SimilarTech data from the equation for reasons stated above, let's look at a summary of we've found:

Metric
W3Techs
Built With

All sites (CMS + non CMS)

-
0.97%
All sites (CMS)
-
-
Top 10m sites (CMS + non CMS)
1.5%
-
Top 10m sites (CMS)
2.4%
-
Top 1m sites (CMS)
-
3.28%
Top 100k sites (CMS)
-
7.73%
Top 10k sites (CMS)
-
12.56%

Clearly, using no-cost data from W3Techs and Built With, it isn't possible for a direct apples-to-apples comparison. But, combined, the data does seem to make sense. If you make the assumption that higher ranked sites have greater complexity and budget, along with the fact that Drupal 8 tends to be focused more on enterprise solutions, then it makes sense that Drupal has a higher percentage of usage among more popular sites.
Can we answer the question "how popular is Drupal?" - well, the answer is "sort of." Often answers to questions like this need caveats, as the table above illustrates. 

So what's the answer? Based on these sources, we're going to extrapolate, and go with Drupal runs about 3% of the top 1 million sites using a content management system as this seems well supported by two independent sources.