Wikipedia defines (computing) cache as
“…a component that transparently stores data so that future requests for that data can be served faster. The data that is stored within a cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere. If requested data is contained in the cache (cache hit), this request can be served by simply reading the cache, which is comparatively faster. Otherwise (cache miss), the data has to be recomputed or fetched from its original storage location, which is comparatively slower. Hence, the greater the number of requests that can be served from the cache, the faster the overall system performance becomes.“
We’ve borrowed a bit from the above for our entry on cache in our glossary module: https://www.itomic.com.au/cache-might-want-clear/
Cache is ‘good’ – and very necessary – because it speeds things up, e.g. the internet.
Cache is ‘bad’ (challenging!) because sometimes you see old information in (for example) your internet browser when you really want to see the newest, latest information. A good example is when you know information on a web page has been updated (probably by yourself), but when you visit the page that’s supposed to have been updated – it hasn’t.
Wouldn’t it be great if you could just push a button and clear (delete) *all* the caching services that sit between yourself and the latest, newest web page information that you’re trying to look at? Here’s the bad news – you can’t, and probably never will be able to. This is simply because there’s cache that’s within your control to be able to clear, and cache that isn’t. That said, it *might* indeed be your web browser’s cache that’s the only cache that is stopping you from seeing the latest information. So clearing your browser’s cache is definitely worth a try.
We’ve found a great article about how to clear your browser’s cache, covering all the major browsers: Chrome, Firefox, Safari, Internet Explorer and Opera. So click that link!
If you’re using Google’s Chrome browser (as most people do these days) then we’ve recently spotted this Chrome extension that can clear all the various types of cache that Chrome uses with a single click: Clear Cache. Very handy. Once installed, be sure to review the configuration options for this extension (Settings > Extensions > Clear Cache Options) so that you can fine-tune exactly what the extension does when you click on the button.
There are other caches you might want to try clearing on your local computer: DNS, memory, and thumbnails. The first on that list – DNS – is most likely to be helpful in relation to seeing updated web page information (especially if your website has just been re-hosted). Here’s an article on clearing all those caches for Windows machine. And here’s another for clearing the DNS cache on a Mac.
If, in spite of all your enthusiastic cache clearing, you’re still not viewing the latest web page information that you expected to see, then either:
- Call your web and/or hosting company (it’s easier if they’re one and the same – like Itomic!). They should be able to help or advise further.
- Er… could you be mistaken? Perhaps the information you’re seeing in your browser *is* the latest there is? 🙂