[big]The online world is full of funny behaviour – and caching can be one of those behaviours that can cause a lot of frustration, or even panic![/big]
There are many layers to caching, both server-side and client-side, and in this short article I want to touch on client-side, or what’s known as Browser Caching.
Browsers like Chrome, Firefox, Safari, etc., are really awesome in that they have a big focus on speed; loading up a website quickly is probably the reason why you prefer one over the other (note: load times are a whole other conversation!). One of their tricks to accomplish this is to cache resources in browser memory so that they don’t have to go and ask the websites’s server for it.
For example, the first time you visit a site you might download a MB or two of data – images, CSS, Javascript – that allow the page to function. The second time however, your browser will look at the resources and say to itself; Hey, I already have that from last time, I’ll just go ahead and use what I have instead of re-downloading all of that. And in most cases that’s perfectly fine!
However, when you’ve made updates to your site, your design, colours, layout, updated a graphic, and other similar things the browser may not know that it needs to re-download that file to get the new version (note: there are tricks to this as well, but the solutions are a little inconsistent). Most browsers do eventually expire their cache and re-download a fresh version, but this issue seems to affect website owners and frequent visitors the most – as that audience is the most likely to have a cached version of many of the files. It’s worth noting the average visitor likely won’t experience a caching issue, so for the most part it’s something you can rest easy on.
