Web Browser Caching, or: "Why Can't I See the Changes My Web Designer Just Made?"

OK, here's another AOL situation. Let's say you're an AOL user. You ask your web designer to make a change to a graphic on your site. She says "OK, the change is done." You go to view the change, but cannot see it and assume that the web designer has made a mistake, when in fact she has not.

Here is what's happening. All web broswers temporarily store the graphics of recently-visited web sites on their local hard drive, so that if a site is visited again within a short period of time, a browser can just pull the graphics off the hard drive vs. pulling them from across the Internet. This allows web browsers to load web pages much faster, because graphics are slower to load across the Internet than text. This process is called caching, and all web browsers do it.

After some time (typically about 4-6 hours), a web browser will toss out it's locally-stored copies of a web site's graphics and will download fresh copies because if the browser continues to load the old graphics, the user will never see new changes made to the site. This process is called refreshing the cache.

But here is where AOL is the exception. By default, the AOL browser takes about 24 hours to refresh it's cache - a lot longer than any other web browser. No other browser holds graphics in it's cache for so long.

You can easily force most web browsers to refresh their cache on-the-spot, just by clicking the refresh button (so you can immediately view new graphics). But I've never seen this work for the AOL browser - it just keeps on using the old, cached graphics no matter how many times you click refresh.

Fortunately, there is a setting in the AOL browser that users can change so that it refreshes it's cache more frequently. I changed this setting once for a client, but this was quite a while ago so I'm not sure the process is the same anymore. Suffice to say, it wasn't hard, so if you use the AOL browser, just snoop around the settings menus a bit and you'll find it.