I was asked about the demographics of no-JS users, and didn't have a great or solid answer ("Corporate intranet users? old browser users? users avoiding banner ads?"), so went looking. Here's what I found:
- Reasons for disabling JavaScript
- Security
- For security - (javascript vulnerabilities in browsers)
- Corporate proxy disabled it - (for intranet security)
- For privacy - (preventing some tracking/advertising systems, usually coupled with disabled-Cookies)
- Preference
- For annoyance prevention - (to prevent things like animations, particularly for users who find these overwhelmingly distracting)
- Performance
- For faster site downloading - (less to download (bytes))
- For faster browser rendering - (less to calculate (complexity))
- Other reasons for which users encounter the no-JS version
- lost connection mid-download - (especially mobile users, and unstable wifi users)
- Methods for disabling JavaScript
- en:NoScript and similar browser extensions
- Browser settings
- Connection proxy
- A browser that doesn't support it - (lynx, etc)
- Prevalence
- 2010 - 1.6% average (2.06% in U.S., 0.26% in Brazil) (according to developer.yahoo.com)
- 2013 - 1.1% in U.K. (according to gds.blog.gov.uk
- 2014 - ???
- (newer stats, and other Reliablesources, would be appreciated. Statcounter doesn't yet reveal no-JS usage)
- Sources and good links
- http://www.punkchip.com/2011/03/why-support-javascript-disabled/
- https://stackoverflow.com/questions/337570/is-it-worth-it-to-code-different-functionality-for-users-with-javascript-disable
- https://stackoverflow.com/questions/9478737/browser-statistics-on-javascript-disabled
- http://webaim.org/projects/screenreadersurvey5/#javascript
- https://gds.blog.gov.uk/2013/10/21/how-many-people-are-missing-out-on-javascript-enhancement/
- http://halls-of-valhalla.org/beta/articles/javascript-disabled-should-i-care,49/
- en:Progressive enhancement
- en:Unobtrusive JavaScript
Let me know if I missed anything major/minor, or add it to the list :)