As testers, have you ever been faced with a situation where the developers think they are much more smarter than you and that you are not really capable of giving them technical suggestions / solutions on how to improve the quality, performance, visual appeal of the website.
Well, here’s a tool that helps you do just that. Well it’s not really a tool so to speak, to be more precise it’s a browser add-on for Firefox that gives suggestions on how to improve the performance of the website. The prerequisite for the add-on – ‘YSlow’ is the installation of the ‘Firebug’ add-on.
The interesting thing about ‘YSlow’ is that when compared with other add-ons like ‘HttpWatch’, it does not only tell you where the problem in performance lies but also tells you how you can address these issues on performance. ‘YSlow’ basically grades sites on a scale of ‘A to F’, A – being the best in terms of Performance and F – being really bad in term of performance. This grading is done considering about 23 rules / best practices that the ‘YSlow’ team has identified which are critical for gauging the performance of a website.
‘YSlow’ assigns a weight for each of the rules and the grading of a website is based on the total weight that a website gains. ‘YSlow’ also assigns a grade for each of the 23 rules so that Developers / Performance Engineers can make informed decisions on how to improve the overall performance of the website. And of course using the ‘YSlow’ add-on, you can always give excellent, well informed suggestions to your developers on how they can tweak their code so that the overall performance of the website improves.
The add-ons for ‘Firebug’ and ‘YSlow’ can be downloaded and installed from the link –
In the screenshot above, ‘YSlow’ has graded the ‘Google’ homepage as ‘Grade A’ for the overall rating. ‘Google’ also gets a grading of ‘A’ for the rule ‘Make fewer HTTP requests’ which is not really surprising considering the fact that the UI of the ‘Google’ home page is quite minimalistic whereas the ‘Google’ home page gets a grading of ‘F’ for the ‘Add Expires headers’ rule where if there is a ‘Expire Header’ assigned to all components on page, the component will be cached and hence there would be fewer HTTP requests the next time the page is loaded. Usually there is a ‘Expire Header’ assigned to images only because of their size but all other components like scripts, style sheets, etc. can be assigned an ‘Expire Header’.
