How do you determine what technology a website is built on?

Question

Quite often I come across a nice looking or functional website, and wonder what technology was used to create it. What techniques are available to figure out what a particular website was built with?

Few frameworks seem to include any kind of generator meta tag like web editors do. Are there any tell-tale signs of particular languages and/or frameworks?

Summary of answers

Site URLs may betray the framework and/or programming language but cannot be relied upon (e.g. file extensions such as .asp). HTTP response headers, cookies, stylesheets and source comments may also give clues.

Some nice tools for querying site details (no doubt there are many more):

Firefox addons:

Wappalyzer - CMS, frameworks/libraries, e-commerce, message boards etc.
Domain Details - IP, country and webserver details
Library Detector - Javascript libraries in use

Chrome Extensions:

Bookmarklets:

WTFramework - shows Javascript framework in use

I like to use [Wappalyzer](http://wappalyzer.com), a Firefox add-on, to see at a glance the site's technologies. — Naoise Golden, Nov 17 '11 at 17:20
http://guess.scritch.org/ is also a decent tool for querying site details. — Ehtesh Choudhury, Jan 28 '13 at 01:30
I would love to know if its a way to hide the underlying server language — shababhsiddique, Oct 06 '13 at 13:10
@shababhsiddique The underlying server language is "hidden" by default. There won't be any standard technique for hiding what your site is built on - just don't let your Backend output any tell-tale markers to the front end — Zach Lysobey, Jan 08 '14 at 21:10
@ZachL still I found a few websites in the past that I couldnt tell was built with. take apple.com for instance. http://builtwith.com/?https%3a%2f%2fwww.apple.com%2f , how do you find out? if you cant find out how did apple hid it? — shababhsiddique, Jun 21 '14 at 03:08

score 67 · Answer 1 · answered Dec 28 '08 at 22:15

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You could use http://builtwith.com to figure out which server and programming language was used. For example it told me that SO uses IIS7, google analytics, html4 and utf8.

If you want to know the framework...well that will probably not be possible just from looking at the site. Why don't you write them an email? ;)

answered Dec 28 '08 at 22:15

Kim Stebel

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Write them an email, well that's lateral thinking for you. Good point! And I like builtwith.com, just need some way to bookmark this answer. Cheers. – Mat Dec 28 '08 at 22:18
Built with cant tell SO is on IIS7 how did you get that info? – shababhsiddique Oct 06 '13 at 13:16
@shababhsiddique: Back in 2008 it could. – Kim Stebel Oct 08 '13 at 19:48
How can I hide my sites info as well? I havent seen any resource yet? – shababhsiddique Oct 09 '13 at 02:54
@shababhsiddique: that is a separate question, you should ask it properly if it doesn't exist yet – Kim Stebel Oct 09 '13 at 13:14

Andy Hume · Accepted Answer · 2008-12-28T22:25:33.813

There are all sorts of things you can look out for, but it doesn't really give you any certainty as to the technology behind a site. In general, information like that is something people will want to hide, as the more information that is exposed the easier it might be for malicious parties to identify security vulnerabilities or denial of service holes.

If I was interested I'd probably look, in no particular order, at:

urls, and file extensions.
HTTP response headers
Source code for comments, or standard JS libraries

Incidentally, the tools mentioned in other answers are only looking at some of the above properties of the site for you, albeit automatically, and slightly quicker. :)

There were lots of good answers so I've somewhat delayed choosing an accepted one, but this fitted best. It covers the basic starting points to use perhaps before delving for automated tools. — Mat, Jan 16 '09 at 21:42

score 8 · Answer 3 · answered Dec 28 '08 at 22:31

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I use 1 plug in for Firefox that gives me the IP and country for the hosting website and it's Web Server name called Domain Details, and for javascript framework I use WTFramework

I still need to wonder what script it was written on, but it is a start :)

Hope it helps.

P.S. the output will be something like this:

alt text http://img88.imageshack.us/img88/2505/200812282328ha0.png

answered Dec 28 '08 at 22:31

balexandre

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glad you liked it :) you can also click the "correct icon" that is bellow the reputaion number for this question so you can mark it as an accepted answer if you wanted ;) – balexandre Dec 28 '08 at 22:38
Any chance you know of a Domain Details Extension for Chrome? – Andrew Hubbs Sep 16 '10 at 03:49
@Andrew did at least try to find it out? it's the first result I get searching on Google! – balexandre Sep 17 '10 at 22:03

score 6 · Answer 4 · answered Dec 28 '08 at 22:07

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URLs can give a lot of clues, especially with Content Management Systems.

For example "http://abcxyz.com/node/46" looks a lot like Drupal.

Also many frameworks have standard JavaScript and CSS files they use.

answered Dec 28 '08 at 22:07

Mel

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Nice! I like the standard javascript and particularly standard CSS files as a fingerprint. – Mat Dec 28 '08 at 22:16
Incorrect. SO uses .NET and has a syntax similar to your example. A website I developed uses the same syntax and runs on Django. – Yuval Adam Dec 29 '08 at 13:11
Same patter of url is used by Rails as well ... For Rails application. You can see same format. For eg : http://mysite.com/post/12 – Rubyist Nov 12 '13 at 15:01

score 4 · Answer 5 · answered Jun 28 '10 at 02:29

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Check out Chrome Sniffer, a great light-weight solution.

answered Jun 28 '10 at 02:29

Jeremy Mack

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Nice chrome extension, as of 2014, it gives you a very complete info of the technical stack. This works great with the BuiltWith extension (the last one gives you more network-related info) – user9869932 Jan 14 '14 at 10:04

score 4 · Answer 6 · answered Dec 29 '08 at 02:32

Some people might even deliberately obscure the technology they use. After all, it wouldn't take me long to tweak apache so that ".asp" actually ran perl scripts and put "powered by Microsoft IIS" into my footer despite the fact I used MySQL.

That way you'd spend all your time trying to hack my site using vulnerabilities it doesn't actually have.

score 3 · Answer 7 · answered Feb 04 '13 at 12:49

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http://guess.scritch.org/ does this for CMSs.

Just pop in the URL and it'll try to guess the CMS. In this case it tells me my blog is running wordpress 3.4.2 (which is correct, I just checked!)

enter image description here

answered Feb 04 '13 at 12:49

matt burns

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It's not good. Only reads page metatags... :( – Silvio Delgado Nov 21 '13 at 13:37

score 3 · Answer 8 · answered Dec 29 '08 at 02:57

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Examining the cookies the site gives can reveal the underlying framework. CodeIgniter, for example defaults to a telltale ci_sessions cookie. Sites using PEAR Auth will do something similar.

answered Dec 29 '08 at 02:57

rooskie

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score 3 · Answer 9 · edited Jul 18 '12 at 16:15

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I use WebParser (http://www.cybermake.com) that allows to determine the CMS used by a website. It allows to determine CMS for multiple websites as well as it can pull the list of websites from the search engines for a given list of keywords. Powerful tool.

edited Jul 18 '12 at 16:15

Mesop

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answered Jun 26 '11 at 00:57

Andrey

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score 2 · Answer 10 · answered Mar 22 '13 at 10:38

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You could use http://builtbased.com/ to figure out which server, framework and programming language was used.

answered Mar 22 '13 at 10:38

Robert Rostomyan

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score 2 · Answer 11 · answered Feb 01 '14 at 10:18

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http://www.similartech.com is a new tool we made, that does just that and presents it very nicely.

answered Feb 01 '14 at 10:18

Eyal

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score 2 · Answer 12 · answered Dec 28 '08 at 22:28

Most ASP.NET sites are easy to identify from the .aspx in the URLs. There are also telltale signs in the HTML source, like a hidden form field named __VIEWSTATE or the WebResource.axd JavaScript. HTML elements will often have id attributes starting with something like _ctl0.

Rails sites will usually include stylesheets from /stylesheets and JavaScript files from /javascripts and each URL will usually have a query string containing a timestamp to thwart caching. Form fields will often follow the naming convention of model_name[attribute_name].

score 1 · Answer 13 · answered Dec 28 '08 at 22:15

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You can use domaintools.com to lookup the server information for a website and narrow down to whether it's open source / Microsoft:

http://whois.domaintools.com/stackoverflow.com

And after that it's a matter of looking in the footer for tip-offs such as "Powered by WordPress" or "vBulletin" etc.

answered Dec 28 '08 at 22:15

Another cool tool I need to find a way to bookmark within SO. I'll have to add these links to the quesion. – Mat Dec 28 '08 at 22:20

score 1 · Answer 14 · answered Dec 28 '08 at 22:15

yes there are some telltale signs for common CMSs like Drupal, Joomla, Pligg, and RoR etc .. .. ASP.NET stuff is easy to spot too .. but as the framework becomes more obscure it gets harder to deduce ..

What I usually is compare the site i am snooping with another site that I know is built using a particular tech. That sometimes works ..

score 1 · Answer 15 · answered Dec 28 '08 at 22:42

Go to Netcraft and use the "What's that site running?" search box in the top left corner. Click here for the report on Stack Overflow. It won't necessarily be correct (e.g., there could be caching or load balancing in the way), but it often gives you the clue you need.

score 1 · Answer 16 · answered Jan 25 '11 at 09:05

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There is also W3Techs, which shows you much of that information.

answered Jan 25 '11 at 09:05

Sam

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score 1 · Answer 17 · edited Nov 19 '12 at 11:19

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In Linux/OSX I often use simple command curl -sI www.site.com

edited Nov 19 '12 at 11:19

Smamatti

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answered Sep 24 '11 at 16:02

basilboli

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score 0 · Answer 18 · answered Jun 03 '09 at 13:26

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http://www.quarkbase.com/ is a very nice tool and information website

answered Jun 03 '09 at 13:26

Amr Elgarhy

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How do you determine what technology a website is built on?

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