We recently had a customer whose website was taking a long time to load.

When we checked it was loading fine.  And we could not really find any issue with load on the server.

Then we used the excellent firebug plugin for firefox to check what elements (css, js, imgs) the site was loading.  And were surprised to see requests to about a dozen different servers, including: google, wordpress, intensedebate, adobe, chatroll, personalizemedia, quantserve, google analytics, facebook, and googleapis.

Each of those requests being slow or failing to load can potentially prevent your page from loading at all, or loading correctly without errors.

Unfortunately this kind of issue is becoming more and more common as websites are pulling in ads, tracking functionality and extra features from more and more 3rd party servers.  Each of these includes can add another bottleneck to their page load performance.  And increase the single points of failure having the page load.

The solution?

• Only include the remotes files you really need on key pages like your home page.
• Install a plugin that lets you see what requests you are making, and monitor them.  e.g. to find out which ones are ‘stuck’ (e.g. because the remote server is having issue) or are slow to load.  Firebug on Firefox is excellent for this.  Safari also has some useful developer tools.
• Where possible load external images, javascript and css so that their failure to load does not ‘take out’ the rest of your page.