|Although Fiddler PowerToy - Part 2: HTTP Performance is quite dated article about Fiddler, I constantly find very useful and practical gems in it. Flagging performance problems by coloring outstanding requests is one of them.||
Quick Resource Box
In the article Eric Lawrence, the author and the creator of the Fiddler tool, shares simple technique of adding custom rules that color outstanding request – be it improper caching or large payload.
Adding Custom Rules To Fiddler
I am using Fiddler v. 126.96.36.199. To add customer rules follow these steps:
static function OnBeforeResponse(oSession: Session)
// Flag files over 25KB
// Mark files which do not have caching information
Testing Fiddler Custom Rules
To test the Fiddler custom rules just navigate to the site you want to inspect. Here is what I get after navigating the home page of my blog:
Highlighting potential performance problems helps quickly focus on it and start improving. Notice the request #3 colored in red – it exceeds 25 KB limit. Request #8 does not have caching header defined for it – colored in purple. Notice also the comments in Custom column. I could go further and and fine tune it, for example filter out 404, etc.
Conclusion and Recommendations
Recent announcement from Google that it incorporates performance into ranking algorithm makes the performance a serious competitive advantage. I can easily imagine new breed Google performance consultants stealing a pie from SEO consultants. I guess it’d be a good move for any SEO consultant to get perf under their belt. Using Fiddler makes it really easy.