node package manager


CLI tool to count the CSS rules, selectors and declarations on a web page.


Counts the CSS rules, selectors and declarations on a web page as well as the total number of inline style blocks and linked stylesheets.

Internet Explorer version 9 and below have a limit on the number of CSS rules & selectors they can parse. Once it reaches that limit, it will fail silently and ignore any further CSS declarations which result in aspects of the page not having styling applied. Additionally, those versions of IE will also fail to parse any stylesheets after the 31st (inline style blocks count towards this total).

  1. All style tags after the first 31 style tags are not applied.
  2. All style rules after the first 4,095 rules are not applied.
  3. On pages that uses the @import rule to continuously import external style sheets that import other style sheets, style sheets that are more than three levels deep are ignored.


  $ selector-detector
  $ [sudo] npm install -g selector-detector

The source is available for download from GitHub.

  $ git clone && cd selector-detector
  $ npm install

Released under the MIT License.