Our series of Tech Challenges are designed to help you get the most out of your devices. March’s Challenge is: Clear Your Cache; a phrase many of us have heard but maybe don’t fully understand why we do it, or how to do it.
What is a Cache?
The word “cache” refers to a collection of similar items that are stored and hidden away. You might have a cache of jewellery, a cache of weapons, or a cache of cash. Your computer stores data in a variety of places, and one of them is the cache. It’s an expensive piece of memory that allows for quick retrieval and faster processing.
Think of the cache in your computer like a table near your front door, holding your keys, wallet and other items you frequently need to grab in a hurry. The more cluttered the table becomes, the harder it is to find what you need, and the slower you are at getting out the door. Over time, certain items become obsolete – like the membership card to the gym you quit which you keep grabbing instead of the new card to the better gym you joined.
What Happens When the Cache Fills Up?
When you ask your computer to perform an operation or deliver information, it starts by checking the cache to try to quickly access what you want. This works well until the cache fills up or the information in it becomes obsolete. That’s when your computer starts to slow down.
Imagine that there’s a website with tons of race car images that you visit frequently. You want to show the site to your friend and you both access it from your laptops in your respective homes. Their laptop instantly pops up with the site, while yours is lagging. When it finally loads, you see empty image boxes with question marks in the centre. Your friend sees motorcycles. You blame your internet connection; your friend wonders where the cars are that you’ve been raving about. What’s going on?
This is an example of how your cache both helps and hinders. Websites are data-rich, with lots of images, fonts, and links. Your computer has to work hard to bring those items from the website’s server to your computer screen. So, the first time you visit a site, your computer does the heavy lifting and then stores data-rich items, like the images, in its cache. The next time you visit the site, it loads faster as your computer pops in the images from its cache.
But one day, the owners of the site change the images from cars to motorcycles. Now there’s a disconnect between what is actually on the site, and what your computer is trying to pull out of the cache to show you. And all those obsolete car images, not to mention images from sites you visited once three years ago and never visited again, are taking up valuable space and slowing things down.
This is why we clear the cache from time to time: to remove obsolete items and free up space for faster processing. The next time you visit the site, your computer will consult the cache to see if it has the information it needs. Your cache will have no memory of having visited this site before and your computer will take a few extra seconds accessing the website’s server to download and store all those new images. The next time you visit, you’ll have motorcycles on demand.
How to Clear the Cache
How you clear your cache depends on which web browser you’re using: Chrome, Safari, Firefox, Edge, Opera, etc. If you want to take our March Challenge to its extreme, clear the cache on all your web browsers on all your devices including laptops, tablets, and smartphones. This article provides instructions for clearing the cache on all major web browsers.
IMPORTANT: When you clear your cache, you will have to sign into certain applications that you may normally be logged into automatically, such as your Google Drive. So before you clear your cache, make sure you’ve done our January challenge and set up a password manager so you can retrieve all your passwords!
Want to Dive Deeper into March’s Tech Challenge?
Interested in learning more about your computer’s cache and terms like “cache hit”, “cache miss”, and “cache mapping”? Check out these articles for a deeper dive:
Good luck with March’s Challenge and we’ll see you in April!