One of the most common questions we get at Drupal beginner classes is, "How can I tell if a site is built in Drupal?"
We get that question because it's just not possible to know the answer without a few tips and tricks.
If you look at a website such as WhiteHouse.gov, there is no way of telling if it's built Drupal. The design of a site is completely independent from the platform it uses.
We're going to give you 5 ways to tell if a site is built in Drupal. Not all of these suggestions will work on all Drupal sites, but taken together they should give you a clear answer.
#1. Source Code
One of the most reliable ways to show if a site is using Drupal is to check the source code.
In the source code, check to see if important files are being loaded from the /sites/ folder. This example is taken from WhiteHouse.gov:
You can search the source code for the words "Drupal":
You can also search the source code for the names of key modules such as "Views", "Panels" or "CCK":
#2. Try to access certain files
Some sites may remove this file or block access to it, but if you CHANGELOG.txt to a site's URL, you can often find useful information about the site. For example, view https://drupal.org/CHANGELOG.txt and you can tell that Drupal.org is still running Drupal 6.
#3. Visit the User URLs
One common identifier of Drupal sites are the URLs for user pages.
The URLs /user/ and /user/password and /user/register/ are commonly used to allow people to login, recover their password or register.
For example, here's https://petitions.whitehouse.gov/user
#4. Use websites
There are websites that can try and identify the technology behind websites.
http://builtwith.com is one of the most popular sites that does this:
It correctly identifies WhiteHouse.gov as using Drupal:
There's also the very logically names http://isthissitebuiltwithdrupal.com:
That site gives very logical and clear answer
#5. Expires header
An expires header is the most geeky way to check for Drupal sites. Web server use an expires header to tell the client how long a component can be cached.
Use a site such as http://web-sniffer.net to check your site:
And in the results, look for the Expires date. You're looking for Sun, 19 Nov 1978 05:00:00 GMT
What is special about 19 Nov 1978? It's the birthday of Dries Buytaert, the founder of Drupal.
If you want to be special too, you can edit this date in the /includes/bootstrap.inc file.