This may not be a question related to programming but I am still asking this since I am banging my head a lot on this issue.
I am finding a lot of HTML5 & CSS3 features useful for my website designing. But as usual (like all developers) I am confused whether to use it or not since older browsers dont support it. (Like css transitions, 3D tranforms, and so on)
I know that I can add fallbacks with Modernizr
Can give alternate stylesheets (If lt IE9.)
Can avoid using css3 and html5
Use html5shiv or similar for adding specific html5 command support.
What my problem is...
I am so fed up of adding so many fallbacks as a developer to every transition/every element which is not supported. So, I thought of few things but not able to choose what to do..
1) Should I totally avoid users still having old browsers and just support latest browsers?
2) Since I am anyway going to make a mobile site with JQuery Mobile separately, should I use the mobile site as a fallback for people with old browsers?
3) Should I continue adding fallbacks and alternate stylesheets?
4) Or, is there any better option?
I am banging my head so badly due to these incompatibility issues. Please give me a suggestion which is developer as well as user friendly. Thank you.
Sùmmary: it depends on your audience. There's no definitive answer to your concerns.
If your target is people who tend to own latest technologies, you can support browsers from 2 years onwards. In the other hand, if your target is people who love staying in old operating systems or you're talking about a large corporation/government, maybe you'll need to provide fallbacks or just skip using edge technologies in order to ensure a proper user experience across all target user devices and browsers.
OP said in some comment:
But I am not sure whether I have to completely scrap support to people with old browsers and alternatively offer them with a mobile based website for pc
If your target has latest tech, why you want to provide a mobile site for PC? You need to decide: if you think that you shouldn't support too old browsers and systems, you shouldn't try to maintain 2 sites when a great percentage of visitors will go to the "edge version". Otherwise, make your main site compatible with older browsers.
BTW, as I said before, there's no definitive answer to your concerns, because it's all about taking a decision and the time will tell you if it was right. Use analytics, check what are the most used Web browsers in your site and provide fallbacks when you detect that there's a high percentage of visitors using old browsers...