Broadband connections mean nothing for users if your site is slow because it’s poorly coded or thought out.
YSlow, a new plug-in that integrates with Firebug , has just been released by Yahoo’s Expectional Performance Team to help you pinpoint and fix specific trouble spots.
YSlow evaluates 13 different performance factors and provides a letter grade to each. If for any reason you fail to score a straighth ‘A’, YSlow will provide additional detail to help you solve the problem.
Let’s see how sitepoint.com did:

Overall 64/100 (or a “D”) largely because we don’t use a CDN (Content Delivery Network such as Akamai) nor Entity Tags.
Aside from rating performance factors, YSlow provides useful stats on the loading size of your website, for both brand-new visitors as well as return users who might have portions of your site still in their cache. Here’s how it looks:

Update: All the performance rules are described on Yahoo’s site.
Related posts:
- Slow Down! 5 Important Questions to Ask Before Taking on Rush Projects Do you take on rush projects and then regret it...
- Why Your Website Statistics Reports Are Wrong, Part 3 In the final part of Craig's series about website reports,...
- Why Your Website Statistics Reports Are Wrong, Part 1 There are lies, damn lies, and statistics. Then there are...
- How to Tell Organizations Their Website is Inaccessible The W3C Web Accessibility Initiative has released a guidance document...
- Build a Money-Making Website in 10 Minutes With DevHub DevHub is a new online website builder that promises a...







The CDN thing to me seems a bit overboard and makes the tool less useful for most developers.
July 26th, 2007 at 6:44 am
Thankfully, you can modify the scoring mechanism by editing the about:config file in Firefox.
July 26th, 2007 at 6:50 am
I fail to see how a CDN is useful to small/medium projects?
Certainly a topic for a blog post or article in the future.
July 26th, 2007 at 2:16 pm
Justifying the usefulness is easy, justifying the co$t is another thing entirely.
July 26th, 2007 at 5:53 pm
It’s a mild irony that this site reviews YSlow when Sitepoint’s website is one of the slowest websites to load that I read.
July 26th, 2007 at 6:10 pm
I like the way that the page for YSlow is actually graded an F.
July 26th, 2007 at 7:06 pm
It’s “Exceptional Performance” not “Expectional Performance”, although, typo or not, expectional does seem like a more fitting name for it. It all comes down to user perception and expectation. A lot of users will put up with a slow site if they expect it will be. Matt being the case in point for his comment on Sitepoint’s loading times.
July 27th, 2007 at 10:13 am
July 27th, 2007 at 10:59 am
<script>alert(”XSS”)</script>
July 27th, 2007 at 11:04 am
Seems you also need to know a fair bit of jargon to understand what you’re being told. What with eTags, CDNs, gzip components and http requests, it’s not for the beginner, I’d say (as a beginner).
July 27th, 2007 at 11:35 am
Speaking of – can someone point me to how-to’s to enable gzip and expires headers? I was thinking in .htaccess, but that just seemed to break my site. Any links to info?
July 27th, 2007 at 11:43 am
I couldn’t understand CDN and ETags. Can you explain the advantages of it?
Thanks
Robin
July 27th, 2007 at 1:44 pm
A CDN is a content delivery network which caches media content (images, videos etc), mirrors the content to lots of different servers around the world and delivers them to the user from the most appropriate location (e.g. the server that’s closest to the user). Lots of companies use them. The most common one I have seen is Akami which serves Apple.com’s images.
July 27th, 2007 at 7:36 pm
this book explains all the performance rules:
High Performance Web Sites
July 28th, 2007 at 3:05 am
it is incredible how many dumb, arrogant idiots surf the web just to leave their spammy and pointless comments.
Sitepoint site is not slow it just features a lot of content unlike your undegraduate resumeè that u mantain on university free space.
Dear jim if all you know about xss attacks is that pathetic 1995-style javascript alert, I suggest you buy some sitepoint’s fine book on the topic and get a bit more knowledge.
p.s.
I’m not related with Sitepoint, I just hate idiotic criticism.
July 28th, 2007 at 4:55 pm
Thanks for the heads up on an excellent little benchmarking tool and I think its a great way for beginners to become aware of potential clientside performance bottlenecks, even if they are not sure what the recommendations mean. But hey, that’s what Google is for!
July 30th, 2007 at 1:46 pm
For fun I did a comparison of similar sites and how their YSlow scores stack up.
August 2nd, 2007 at 11:01 am
Not tried it yet, but it looks like it just rates you based on the technology you are using and not actual performance, as to be honest I’d give Sitepoint.com an F for performance, it’s unfortunately one of the slowest sites I visit. Firebug reports 4 seconds to load this page.
August 2nd, 2007 at 11:09 pm
Karl – I agree with you 100%. That’s why we’re investing a lot of time and money into splitting off the MarketPlace & Contests onto their own dedicated server cluster. This will dramatically decrease the load on the articles/blogs/forums sections of our site, thus improving performance.
August 3rd, 2007 at 3:35 am
Good to hear, I do like to keep things “whizzy” when I’m browsing – Else I tend to switch to another browser window and forget to come back to the other one :)
August 3rd, 2007 at 3:38 am