3/7/11
11:30 am

MacMost Now 525: Clearing Your Browser Cache

Your browser temporarily stores images and data in a cache on your hard drive to speed up reloading web pages. But sometimes you may wish to clear your cache to load fresh content. Learn about the cache and how to clear it on the Mac in Safari, Firefox, Chrome and on the iPhone, iPod Touch and iPad.

Video Transcript (Click to Expand)
Hi this is Gary at MacMost Now. On today's episode let's learn about browser cache's and how to clear them. So what is a browser cache? Well as an example say you go to a webpage and there are several dozen images on the page, some of them are part of the logo for the site, the navigation bars and there might be some photos in the middle. What'll happen is these images will be downloaded to your computer so they can be displayed inside the browser. Then if you were to reload the page or visit it later instead of your browser calling after the internet to reload all those images again it will have saved copies of them locally on your hard drive in what is called a cache and then it will load them right from that cache instead of downloading them a second time from the internet. This saves time and bandwith but sometimes having things cached can lead to trouble, say if the page doesn't load correctly, especially if it has more complex content, say maybe some sort of game or other interactive form or something. So sometimes it is useful to know how to clear your cache and load a fresh new copy of a web page. So, in Safari the way to clear your cache is to go to the Safari menu and you'll see an empty cache menu item, right there. Just selected it, it will ask you if you are sure you want to clear the cache and just click empty. Now if you haven't done this in a while it may take a few seconds to clear the cache out. So where actually is the cache? If you go into your users folder, under library, you'll see a caches folder there and you'll see a ton of different folders in here because different programmes use their own cache. They save their own internet loaded data, or maybe user generated data, so it can load it from a file faster than it can actually recreate the content. So you see a lot of different stuff in here and if you look down under Com.Apple.Safari that is where you find your safari browser cache and the cache is actually this .db file and here we'll see that this one is 12 Megs in size if I would switch to the browser here and empty the cache and then look at the database I can see that now that its shrunk to only 25K. Now if you are using chrome instead of safari the way to clear the cache there is to go to chrome and then clear browsing data that will take you to the special webpage, right there, and allows you to check off what exactly you want to clear. So if you just want to clear the cache just have that one selected and click clear browsing data. If you use firefox go to firefox preferences and under there go to advanced and you'll see offline storage and a clear now button. In firefox you can also go into privacy and under that go to, firefox will use custom settings for history, and under there check off clear history when firefox closes settings and you can select to have your cache, just your cache cleared every time that you quit firefox. Now on the iPhone, iPod touch or iPad you can also clear the cache. The way to do that is to go into settings in the settings App click on safari and one of the settings there is simply a button to clear the cache. A few things I've observed about clearing the cache in safari. One is that it doesn't always completely clear the cache there appears to be a memory cache as well as a disk cache. So I find that it is useful to not only clear cache but then quit safari and restart it just to make sure all the images are reloaded fresh from the website. Now it used to be that browsers had a setting were you could specify how long images and data where cached for, that is no longer there on most browsers that because most modern websites will specify for each piece of content how long to cache it for, for instance, if you go a weather website it may have the weather sites logo at the top cached for a long period of time but a little image that shows the current temperature it may say never cache this always load a fresh copy. So, if you're ever told that clearing your browsers cache may fix a problem you are experiencing on a website, now you know how to do it. Till next time this is Gary for MacMost Now.

Comments: 4 Responses to “MacMost Now 525: Clearing Your Browser Cache”

    Richard
    3/7/11 @ 10:32 pm

    I went to my cache folder in my users name and saw tons of folders of caches in folders. Can I delete the folders with the caches in them? Good or bad idea.

      3/7/11 @ 10:45 pm

      Bad idea. Caches are created to increase performance of the application that uses them. Why would you want to decrease performance by deleting them?

      Stuart
      8/2/12 @ 1:20 am

      It doesn’t really matter if u do or not but it’s a good thing if u do choose to because it will speed up ur safari and possibly speed up the device tht u are using but most of the times u will not he able to tell a difference. I just cleared mine like 5 min ago. I make it a regular thing to keep my device running smoothly.

    Mr Anthony Cotton
    7/25/11 @ 2:00 pm

    Again this video makes it easy to understand. I did not have a clue what the cache was for,so i did not touch it in case it caused a major problem. The thing that put me off emptying the cache was the the drop down. Saying if you delete this you will loose something. This to me was a warning not to empty your cache. It has not been emptied since i bought my computer, but i will watch your video again,and just go through it slowly. Thanks Again Gary

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