I&apos;ve noticed in conversations that a lot developers really do take page size for granted. Their rationale is usually that their target audience uses broadband so there&apos;s no need to worry about it. I call that naive thinking. You still need to be cognizant of what you&apos;re building and how its coming across the wire. Large pages can still be excruciatingly slow, even on broadband, so you can&apos;t take that for granted.

Well, <a href="http://www.yahoo.com">Yahoo!</a> just made it way easier to see what&apos;s slowing down your pages. The <a href="http://developer.yahoo.com/yslow/">Yahoo! YSlow</a> Firefox plugin "analyzes web pages and tells you why they&apos;re slow based on the <a href="http://developer.yahoo.com/performance/index.html#rules">rules for high performance web sites</a>". Considering that Alexa ranks Yahoo! as the top visited site on the Internet, I would say they know what they&apos;re talking about.

What I really like about this plugin is that it integrates directly with the Firebug console so you don&apos;t have some extra widget sitting in FF and it also provides a summary of the target areas that you should address to improve site performance. This summary is in the form of links which take you to an explanation of why a specific area is important. I&apos;m really digging this.

If you&apos;re really serious about having a responsive site, you should consider adding <a href="http://developer.yahoo.com/yslow/">Yahoo! YSlow</a> to your toolbox.


<b>Update:</b> Stoyan Stefanov has done an excellent review of YSlow <a href="http://www.phpied.com/yslow-performance-extension-for-firebug/">here</a>.