Many web sites fall in the middle of these metrics. For these sites, the best solution generally is to deploy the JavaScript and CSS as external files. The only exception where inlining is preferable is with home pages, such as Yahoo!'s front page and My Yahoo!.
Home pages that have few (perhaps only one) page view per session may find that inlining JavaScript and CSS results in faster end-user response times.
For front pages that are typically the first of many page views, there are techniques that leverage the reduction of HTTP requests that inlining provides, as well as the caching benefits achieved through using external files. One such technique is to inline JavaScript and CSS in the front page, but dynamically download the external files after the page has finished loading. Subsequent pages would reference the external files that should already be in the browser's cache.
Anna Taylor on 17 Jun 13Does your web site or marketing email look as good on all mobile phones and other handheld devices, as it does on your computer? If not, you have a bigger problem than you realize..
