A: Many tools can help you identify what is taking time for your website to load. Reasons for slow loading can include the end user’s web browser having to download too many files (remember every image and style sheet is a separate download the browser has to perform), files not compressed, and more.
The first tool I normally use is PageSpeed from Google, which has add-ons for both Google Chrome and Mozilla Firefox.
You’ll see a Page Speed tab that offers details about your web page download performance and a score telling you basically how optimal your site is. (See screen shot below.) You can click each item to get guidance on how to make your site perform better.
Another solution, called Whyslow, performs an analysis and displays why your website isn’t performing. It has a free option to check your site from various locations around the world to see how long it would take to download from those locations. (See the screen shot below.)
You can get a report by giving your email address, and the report should arrive within a few minutes.
Like Page Speed, an add-in is available for Firefox that utilizes Firebug and can be downloaded and installed from the Mozilla site. It’s called Yslow.
YSlow also gives a score of how your website is performing. This score varies from the score Page Speed provides, as the two use different metrics. Your goal should be 100 for both YSlow and Page Speed, but that is very difficult to achieve. (See the screen shot below.)
To see how long each file of a website is taking to load, and the order in which they are downloaded, you can use Internet Explorer and press F12 to open its Developer Tools (I'm using Internet Explorer 9.0).
Select the Network tab, and select Start capturing. Press Ctrl as you refresh to make all pages download from the website, and you’ll see the detail of the downloads.
Note that it downloads the main HTML file first, and then from that file it can then download all the files contained in that main HTML page. The white in the graph is the time from when the request was created and when it was actually sent; the yellow is the time the request for the data took to send; and the blue is the response time to receive the requested data. (See screen shot below.)
By using IE network capture and the YSlow and PageSpeed add-ins, you can get great insight into how sites perform when downloaded and also see ways to improve them.
Read more FAQs on all kinds of admin issues at John Savill's FAQs for Windows!