How Many Websites Use Drupal? Let's Estimate A Number [Part One]

We work with WordPress and Drupal. According to wordpress.com, there are 25.2 million WordPress sites as of July 2010. How many Drupal sites are there?

Very short answer:

Nobody knows for sure. But we think at least 7.19 million websites use Drupal as of July 2010, including hundreds of the world's most prestigious sites. Whatever the exact number is, it's growing exponentially.

Very long answer:

Since there are no exact numbers and no perfect ways to find exact numbers (in fact, the community lost count pretty much right away), we have to attack this from a few angles.

Angle 1: Compare Drupal's Market Share To WordPress' Market Share

Here's how the software used by the 10,000 most popular websites breaks down, according to Backend Battles, which is a website technology monitor and not a dance contest:

141 of the 10,000 most popular websites run on WordPress. 39 are based on Drupal (making them the web's two most popular content management systems). So Drupal has 27.6% of WordPress' presence on the Backend Battles list.

BuiltWith Technology Trends is similar to Backend Battles, but uses a larger sample size of 100,000 sites. According to BuiltWith as of July 2010, WordPress is used by 3.09% of websites, and Drupal is used by 1.67%. BuiltWith suggests Drupal has 54% of WordPress' user base. (Grain of salt: BuiltWith has been known to think everything's Drupal, like it's a kid in Sunday school answering every question by saying, "Um, the Bible?", but they claim they've fixed that by now.)

If we extrapolated Backend Battles' 27.6% and BuiltWith's 54% to the entire web, we could suggest that there are either 7 million or 13.6 million Drupal sites on the entire web. An average of the two would be 10.3 million. But that's likely too high. More on that in a second.

We'd arrive at these numbers by applying the Backend Battles and BuiltWith percentages (27.6% and 54%) to the number of total WordPress sites among the entire web (25.2 million as of July 2010), not just among the most popular 10,000. Because if Drupal has X% as many sites as WordPress among a sample size of 10,000 sites, it's reasonable to think the percentage would stay similar even among a set of all sites.

10.3 million: too high or too low?

On the one hand, the total number of WordPress sites includes both self-hosted sites that use WordPress software and blogs hosted on wordpress.com. The sites measured by Backend Battles and BuiltWith are the web's most heavily trafficked sites -- almost all of them are self-hosted. Most blogs hosted on wordpress.com are going to be less popular than the web's 10,000 or even 100,000 most popular sites. The density of total WordPress sites is only going to swell the deeper we go past the most popular sites. Anyone can start a wordpress.com blog in seconds, and then never touch it again. Surely that's boosted WordPress' numbers quite a bit.

Drupal, however, doesn't have any widely adopted instant-website solution. If you want a Drupal website, you've got to really want a Drupal website -- committing to downloading, installing, and setting up Drupal is a bigger barrier to entry than WordPress usage faces. (Drupal's trying out Gardens as a quick-and-easy, WordPressy, hosted-for-you deal, but it's not likely to catch on because the freaking URL is drupalgardens.com.

Imagine telling someone in a loud bar, "You should check out my blog. It's at partyface.drupalgardens.com."
Their reaction would be: "Partyface what gardens dot com?"
You: "D-R-U-P-A-L. I think it means rain in Norweigan; it's got modules."
Them: "Partyface dot D-R-U-P-A-L dot gardens dot com?"
You: "Close, but no. Let's walk through this one more time."

Digressing.)

On the other hand, as this Joomla chart suggests, open-source CMS usage tends to be more prevalent once you venture past the top 100,000 sites, though perhaps none more so than wordpress.com-hosted blogs.

Brain hurts. Here's what's happening: cutting that Drupal average by 20%, a totally arbitrary number, to account for the wordpress.com thing.

Angle 1 result: 8.24 million Drupal sites.

Another web software monitoring site we considered, W3Techs, was way out there: Drupal has only 11% of WordPress' presence. On its face, that's not totally unreasonable -- 11% of WordPress' 25.2 million sites would suggest there are about 3 million Drupal sites, which is much lower than the others but not outrageous. However, they're only counting domains, not subdomains, meaning their numbers would only give WordPress credit for its 13.8 self-hosted sites, not its 11.4 wordpress.com-hosted sites. And 11% of 13.8 million is only a million and a half A MILLION AND HALF. As we'll get to in Angle 3, Drupal was downloaded more times than that during the third-biggest year of its shelf life, let alone its other eight and a half years A MILLION AND A HALF.

Angle 2: Look At What People Are Searching For

According to Google Trends as of July 2010, WordPress gets searched 3.2 times more often than Drupal does. Even though WordPress appears to be soaring while Drupal plateaus (we’d prefer the term consistent, even though Drupal clearly was Googled more in 2009 than it was in 2008), the difference is between 2.1 x and 3.5 x for every calendar year so far. Therefore, WordPress has had about 3.2 times the popular interest Drupal has had. Popular interest is relevant here because more searches are going to mean more downloads/signups YES I KNOW not directly, but I can’t imagine how there wouldn’t be some kind of correlation there. (Then again, Joomla was searched more often than WordPress was for three straight years, and there aren’t as many Joomla sites as there are WordPress sites; Joomla has been downloaded 14 million times since 2007 according to joomla.org as of May 2010 in a long string of prepositional phrases without a comma. A fine number if it’s accurate, but not enough to approach 25.2 million. Sometimes all you can do is throw your hands in the air and proceed as planned. Watch me do that in the very next paragraph.)

Assuming X number of searches translates to Y number of new sites, we can again use the 25.2 million total WordPress sites as a base point. Dividing 25.2 million by 3.2 gives us 7.9 million, remarkably close to our 8.24 million estimate from Angle 1. Now let’s dock it by OH GOSH SAY 20%, because of the previously noted wordpress.com-hosted thing.

Angle 2 result: 6.32 million Drupal sites.

Angle 3: Expand On What We Know About Drupal Download Stats

Our first two angles depend pretty much entirely on the data that the WordPress organization has chosen to release to the public. They’re not known exaggerators, but our whole house of cards would be zoning violation’d if their numbers were off. So let’s try and do one independent of WordPress.

From 2006 to 2008, Drupal founder Dries Buytaert posted annual download stats, but hasn’t done so since. That’s fine. As with Joomla and WordPress above, we’ll assume they’re accurate.

Drupal downloads per year:

• 2005-06: ~300,000
• 2006-07: 600,000+
• 2007-08: ~1,600,000

That’s almost 2.5 million downloads right there. More than two years have passed since the most recent update. If downloads continued at 2008’s pace, that would equal 5.7 million downloads, plus whatever happened between 2001 and 2005 — let’s say ~300,000 total for Drupal’s first four years. That might seem conservative, but it still adds up to 6 million. Of course, there’s reason to believe (based on our sources for Angles 1 and 2, plus other factors*) that demand for Drupal has risen in the past two years, so 6 million is too low.

* BuiltWith finds Drupal to be among the web’s 50 fastest-growing technologies between April and July 2010. DrupalCon attendance continues to double. 20% of Drupal’s total module projects were begun in the past eleven months (4,600 in August 2009 according to Wikipedia, 6,190 on drupal.org as of July 2010). The many high-profile organizations that continue to convert to Drupal (in the past few weeks: the U.S. Department of Commerce, South Africa’s World Cup site, and Christina Aguilera, among others). And so forth.

Sure, a Drupal download doesn’t equal a new Drupal site. There are many reasons why a download wouldn’t end up becoming a full-fledged site — people could download just to try out Drupal or test a module, for example. But let’s say this is balanced by: (A) one download could spawn 1,000 sites if a developer was so inclined — none of which are counted here, (B) there are plenty of other places besides drupal.com from which to download Drupal (if we felt like it, we could host it for download right here), (C) there are dozens of custom Drupal distributions like Acquia, iSite Essentials, Open Publish, and Pressflow that aren’t counted (D) alpha, beta, and release candidate downloads — most of which could yield a fully functioning site — aren’t counted, and so on.

Bumping that 6 million up by 1 million to account for Drupal’s increase in popularity since 2008 is very reasonable. Downloads almost tripled between 2007 and 2008, and we’re certainly estimating a much less aggressive rate of increase than that. Yep, that puts us right within range of our previous two estimates, which might seem like we’re forcing the numbers to fit. But, using 6 million as our base number, how many do you suggest we add to account for Drupal’s mini-surge of 2009 and, to a lesser extent, 2010?

Angle 3 result: At least 7 million Drupal sites.

Crappy, Discarded Angle: Search For How Many Sites Still Have The “Powered By Drupal” Badge

Every stock Drupal install includes a little footer badge with the Drupal logo and some alt text that reads, “Powered by Drupal, an open source content management system.” Most people take it down; some people leave it be. You’d think searching for this would be useful — no, not really. Depending on the search engine (and, seemingly, the time of day, ozone levels over Nepal, and LeBron James’ number of Twitter followers) it returns anywhere from 60 million results to 40,000. There are nowhere near 60 million Drupal sites that haven’t removed their showroom stickers yet, and there are a whole lot more than 40,000.

Even using Yahoo! Site Explorer and filtering to only include sites that link back to drupal.org, as the badge does, isn’t helpful. I tried several different variations of the same kind of search, all of which wound up under 100,000.

This angle is like 89 degrees — it ain’t right. (And yes, this means there weren’t 40 million freaking Joomla sites two years after it was created.)

Angle 4: Fly Everything Up The Flagpole And See Who Salutes

Averaging the results from all three previous reasonable angles — because why not? — gives us 7.19 million. And until somebody comes up with a better idea, that’s our answer. Please come up with a better idea.

We estimate there are about 7.19 million Drupal sites, and we’re not as un-confident about that as you might think we should be. Your turn?

(7.19 million, and we just want to build you one.)