How does BuiltWith.com work?

When you lookup a page on BuiltWith, a robot goes off deep into cyberspace and looks at the page in question. It them compares that page with the technology list at BuiltWith.com and if it finds any matches, reports the information to you.

Does BuiltWith.com use reverse engineering?

No! BuiltWith.com doesn’t do any trickery to find out what technologies a page is using. All the information that BuiltWith.com reports on can be found yourself by clicking View..Source in your browser.

Doesn’t reporting this information make it easier for hackers to get into my site?

No! See the last question.

BuiltWith.com says a site uses [technology] but it doesn’t, what is going on?

A number of reasons can cause this -

1. BuiltWith.com detects technology by matching substrings of the technology name. If a page contains a matching substring it will report the page as featuring that technology.
2. BuiltWith.com caches search results, it may be possible that the page has been modified since the technology was used.

Builtwith.com doesn’t find [technology] on the site report but I know it uses it.

Reasons why -

1. BuiltWith can only report what it finds, if your site uses a technology but there is no information to suggest the technology exists it will not report it. BuiltWith relies on default settings, for example, if you use Scriptaculous JavaScript library but don’t use the filename scriptaculous.js there’s no way it will be found.
2. The technology isn’t listed. If this is the case visit the Suggestion Page to add or modify a listing.

%age of sites using a given technology seems a bit wrong?

The percentage of sites using a technology is a static process that happens every now and then (it is a manual process at the moment). Hence the figures may seem off.