DEV Community

Discussion on: User Agent Reduction in Chrome, Safari & Firefox

Collapse
 
ingosteinke profile image
Ingo Steinke, web developer

Several feature detection options can be done in JavaScript or in CSS, and of course we should design our websites and apps using responsive design and progressive enhancement. HTML and CSS are more robust than JavaScript and browsers must ignore unknown elements and directives by design.

Apple has reduced their user agent information for a long time now, especially for iPhone, the device most notorious for outdated buggy browsers, so there are obscure feature detection combinations hopefully only targeting a specific range of mobile Safari.

We have been told not to rely on User-Agent strings for twenty years, but still, many web services do, including Cloudflare and Google. Try adding "Vivaldi" to your user agent string and see what happens and how many websites will show you a warning or don't let you use their service at all. That's how you lose customers.