Is writing a cookie very slow in JS?

Question

I need to make my website faster on the client side. I wonder if my excessive Javascript cookie manipulation could slow down the browser. It uses the harddrive, which is the slowest component of a computer. On a severely fragmented harddrive, could cookie manipulation freeze the browser?

Is JS doing any optimizations for cookie writing/reading (caching, etc..). Could I exploit these optimizations to improve my site?

Replacing client-side cookies with a server side database is out of the question because my servers are overloaded already.

Answer 1

There are a few ways you can speed up your page on the client side, although I'm guessing reducing cookie use would only save a few microseconds at best. Just in general make sure you are only saving what you need.

There are tons of other optimizations that you can do though, such as:

• Serving your files as gzipped content
• Ensuring as much of your site is cache-able
• Using CSS sprites and combining javascript + css files to reduce HTTP requests (will reduce load from your server too)
• Minifying your javascript, css and html

These are all proven methods of reducing page load times.

For more information on how to make your page load faster, get the YSlow! plugin for firefox / firebug http://developer.yahoo.com/yslow/