Is designing websites for IE9 meaning, that it's compatible with everything

[RikTelner]

I have following (really long) statement:

When I develop website that is entirely compatible with Microsoft Internet Explorer 9, and make it work foulless, I'll make sure that website doesn't require JavaScript to run, and I will make it work entirely without it. Afterwards I will add CSS3 little tweaks to make it look better (with CSS2 fallbacks). Afterwards I'll add JavaScript enhancement to make operations smoother. I will catch 99% of people in the world (browser support/JavaScript support) and website could be technically considered WELL made.

For this statement I need you to assume following things:
- We're talking about April 2016.
- Website has to be compatible with every (old) browser that has been made after or exactly at date of release of Microsoft Internet Explorer 9 (this includes Safari/Opera/Chrome/Firefox versions).
- Website will be responsive (if possible) (incl. mobile devices and 4K television etc.; excl. smart-watches etc.)
- Browsers that don't support CSS3 properties will look/work good without them (as they will have good/sufficient CSS2 fallbacks).
- Website works without JavaScript, but works better with it (progressive enhancement).
- The code will feature some CSS3 code, but as there will be fallbacks, there will be errors such as "invalid property", which can be ignored if browser's too old to know that it's valid value.
- The design is appealing.
- I might've forgotten about something.

Could someone prove me wrong or confirm this?

[rproffitt]

That could make for a very dated web site. Add the fact you want it to work on next gen devices like 4K displays (nit: running into few 4K displays, most are UHD!), my bet is you need to use features that blow IE9 out of the water.

Check your use of features with some sites like:
http://caniuse.com/
And of course W3C's site and code checker.

PS. What is "foulless"? Maybe faultless?

[RikTelner]

That could make for a very dated web site.

Dated?

Add the fact you want it to work on next gen devices like 4K displays

Next generation devices? They're here, and there's many of 'em!

my bet is you need to use features that blow IE9 out of the water.

How so? It's still CSS2, with @media. According to caniuse.com
http://caniuse.com/#search=%40media
I can easily use Internet Explorer 9 with it.

Check your use of features with some sites like:
http://caniuse.com/
And of course W3C's site and code checker.

Of course.

PS. What is "foulless"? Maybe faultless?

Excuse me, I'm not native Anglophone speaker (or writer). I took word "less" as in (deprived of) and "foul" as in "flaw". But yes, "faultless" is better word for it.

But what about the statement :( ?

[rproffitt]

The statement? I'll disagree. It's a big list to look at but https://msdn.microsoft.com/en-us/library/dn467850%28v=vs.85%29.aspx?f=255&MSPPError=-2147217396 notes changes that for this round let's say your site was perfect in IE9 but used elements and features in MSFT's article could indeed fail on later IE versions.

So, it is possible to make an all good with IE9 web site yet see failures in other browsers including Microsof'ts own.

--> So with that my guess is you are chasing the low sought after "I want my site to be compatible with all browser" dream. That's a dream!

[RikTelner]

What about conditional comments? Couldn't I redirect IE9 and IE8 to seperate subdomain for oldies?

[rproffitt]

Sorry about that typo. I meant long sought after.

As to the conditional statements, yes, that's how many sites work around all this.

But, that's a lot of work. RWD ( https://en.wikipedia.org/wiki/Responsive_web_design ) is a primer on this. Many sites try to be responsive and fail in another way.

See https://xkcd.com/869/

[ryantroop]

Develop for what your customer base is likely to be using. I still support IE9, but I have to keep current with changes, and develop new features for future browsers. caniuse.com is an excellent resource. Use it. Know why you are implementing things, and how to fall back when you can't use the new.

Also, if people are disabling javascript they are likely going to be used to jacked up websites, or sites that don't quite work the way they expect. If you feel that you user base will be very very against javascript, then develop this way - otherwise, join 90% of the web and don't worry about it.

A better way to look at development with JS is this -> Is it stylistic? Do it in CSS. Is it Data? Do it in javascript. Is it functional? Try to avoid JS unless its part of the functionality in the first place (FileReader, all the new fancy HTML5 stuff, canvas, etc...). There are always going to be times when the lines get blurred, and sometimes you need the helping hand of javascript to make your CSS look right.

[gentlemedia]

This is how I approach any project:

1. Define the core functionality
2. Make that work without any bells & whistles (even if the UX sucks)
3. Enhance