Is it really possible to achieve grade "A" in yahoo's yslow for all things for a dynamic/CMS website?

Question

Is it really possible to achieve grade "A" in yslow for all things for a dynamic and CMS(PHP/Asp.net) based websites? and using same server.

http://developer.yahoo.com/yslow/help/index.html#performance_view

Answer 1

Sure, why not?

Each item follows through to a link with more details on how to acheive a higher grade

Answer 2

Yes, I guess it is possible to achieve this on one server, except of course for the CDN part which relies on an external service. You'll probably need full control over your server to configure things like ETags and such.

I think it's rarely worth the effort to fulfill all this literally down to the last percent except if you're a huge site like Google or Yahoo themselves, where every saved byte can mean tens or hundreds of thousands in savings. Just get a proper grade so things work fast and reliably - much like in school :)

Answer 3

Yes. First of all, try making any and all of your JS external, and load it on demand, only preloading the components that you really need. Then monitor when each javascript file is loaded, in order. Run that through JSBuilder (JavaScript packaging and compressor tool).

Turn on GZIP on your server. Gzip compression was able to reduce my static filesizes (css, js, etc.) by 73.43%.

Cache, cache, cache. Anything that doesn't change between application deployments needs to have a far-future expires header.

If you can afford it, serve your files from a cdn. They are distributed networks that make delivering content easier.

Get rid of your cookies, or combine them by encoding their values in JSON or using a caching service server-side to cache the values, and only store the cache key in the cookie. That way you only have one cookie instead of hundreds.

Put your css at the top, and optimize it by stripping out any unused selectors and properties.

Oh, and consider switching to a thin client...reloading the web page is so 1999. Using a thin client allows you to try different page download optimization techniques, and decouples your view (the web client) from your server and middleware api, allowing you to develop a front end in just about any RIA environment of your choice. You can go extremely lightweight with JQuery, or go with the more robust pre-built UI's of Ext or Dojo.

Reduce the amount of unused HTML. Tables are evil unless absolutey necessary or inserted into the dom after page load.

I'm sure that some of this will require some major re-work, which your application architecture and developer skill set may not be geared for at this time. The good news is that you can improve your user-experience just by cacheing cookies server-side (like I mentioned above), gzipping your static components, and combining and minifying any and all JS, and optimizing your CSS and layout, without getting into re-structuring your web application.

Answer 4

Yes, it is possible.

Here is a guided success example of an optimisation of a Typo3 installation. Take a look at this Yahoo! page for optimisation goodies.

Is it worth trying to optimise for bandwidth reduction and server responsiveness? Sure! A lot of people connect through hand-held devices with expensive mobile phone plans. The school system where I live even have limited and expensive broadband plans. Waiting for a website to load is a waste of time.