How can I force clients to refresh JavaScript files?

Question

We are currently working in a private beta and so are still in the process of making fairly rapid changes, although obviously as usage is starting to ramp up, we will be slo

Answer 1

One solution is to append a query string with a timestamp in it to the URL when fetching the resource. This takes advantage of the fact that a browser will not cache resources fetched from URLs with query strings in them.

You probably don't want the browser not to cache these resources at all though; it's more likely that you want them cached, but you want the browser to fetch a new version of the file when it is made available.

The most common solution seems to be to embed a timestamp or revision number in the file name itself. This is a little more work, because your code needs to be modified to request the correct files, but it means that, e.g. version 7 of your snazzy_javascript_file.js (i.e. snazzy_javascript_file_7.js) is cached on the browser until you release version 8, and then your code changes to fetch snazzy_javascript_file_8.js instead.