When using your computer or smartphone, you may have the impression that if your computer or smartphone becomes slow or runs out of free space, you can improve the performance by clearing (= deleting) the cache.
Although “cash” is often explained as if it were “something we don’t need,” it actually has a solid meaning and is useful behind the scenes. This time, we will explain about such cache, how it works, and how to clear it.
What is cache?
Cache is a mechanism that temporarily stores information about web pages that you have viewed once in each browser.
When the cache is saved, the display speed of the web page once viewed increases. There are also ”
cookies
” which are quite similar but have slightly different characteristics.
First, I will explain these two points.
Cache increases display speed
Caching increases the display speed of web pages once viewed. Normally, when displaying a web page, various data such as images and text information are sequentially downloaded from the web page, so the problem is that it takes some time.
However, if the device has a cache, it reads the information from the device and redisplays it on the screen instead of downloading the information from the web page.
The speed of reading the cache of the terminal is faster than the speed of downloading and displaying data, so the display speed increases.
There are also “cookies” that are similar to caches.
Cookies are similar to caches. Cookies are a mechanism that stores information about users who visit a web page. Cookies are used to memorize ID and password entries and automatically log in, which you probably use on a daily basis.
Cookies are similar in that they are “mechanisms that allow users to view web pages comfortably,” but caches record the contents of the web pages themselves, and cookies record the contents of inputs and operations within web pages. Their characteristics are different in this respect.
Advantages and disadvantages of cache
Now, cache is a useful feature that increases the display speed of web pages, but it has clear advantages and disadvantages.
Benefits of cache
It has the following advantages:
I will explain each one.
Faster loading times when reloading pages
By saving cache, the page display speed becomes faster because almost no data is downloaded from the web page, and the information stored on the computer/smartphone is read.
Saves automatically in each browser
Cache is automatically saved in each browser without you being aware of it. It automatically uses the cache that is automatically saved to make browsing web pages more comfortable.
It is possible to save on communication amount.
There is no need to download data from a web page every time, so it also has the effect of saving communication traffic. With some contracts for smartphones, etc., charges are added based on the amount of communication, so reducing the amount of communication is a big benefit for users.
Disadvantages of cache
It has the following disadvantages.
I will explain each one.
Old content may be displayed
When displaying a cached web page, downloading new data from the web page is omitted, so even if the content has changed, the old content may be displayed as is.
To avoid this, it is necessary to reload using the reload function “Super Reload” that does not use cache, or to clear (delete) the cache.
If too much cache accumulates, the device may become heavy.
When the capacity of the cache itself becomes large, it places an extra load on the device and may cause the device to freeze or become heavy.
Also, especially in the case of smartphones, it may take up too much space and you may not be able to save the data you need. To avoid these, you need to set a limit on the storage capacity of each browser’s cache or clear it.
Countermeasures against the disadvantages of cache
There are three ways to counter the disadvantages of caching:
We will explain each measure.
Perform a “super reload”
“Super reload” is a method of reloading the information on a web page without using cache. This allows you to save the cache and reload new information for pages that have been updated.
Super Reload can only be used on a computer, so if you are using a smartphone, you will need to clear your cache. Here’s how to do a super reload:
This operation allows you to easily perform a super reload and load information on a new web page.
Setting an upper limit on cache capacity
The method of setting the cache capacity limit varies greatly depending on the browser, but by setting a limit, old cache is automatically deleted, which may slow down the operation or prevent data from being saved due to capacity constraints. prevent you from doing so.
Clear the cache
The cache can be cleared (deleted) manually. Because the cache is automatically saved, information from web pages that are never displayed a second time accumulates, and the capacity increases due to the cache including unnecessary information.
We recommend that you periodically clear your cache to prevent old web page information from displaying and from becoming too large.
Cache clearing procedure
We will explain the steps to clear the cache. The operation method differs depending on the device and browser, so we will explain the method for each medium below.
For iPhone/Safari
You can clear the cache on iPhone and Safari by following the steps below.
1. Open “Settings”
2. Scroll down and select “Safari”
3. Scroll down and select the blue “Clear history and website data”
4. Select “Clear history and data”
However, in the case of iPhone/Safari, you cannot delete the cache alone; you must be careful as it will also delete your browsing history and cookie information.
For Android smartphones
Although the notation for Android smartphones differs slightly depending on the version and type of device, the general steps are the same.
You can clear the cache on Android smartphones by following the steps below.
1. Open “Settings”
2. Select the item labeled “Device capacity” or “Storage” and select the item related to the app.
3. Select the browser app you are using and select the item labeled “cached data” etc.
4. You will be asked “Do you want to clear cached data?” Tap “Yes” or “OK”.
In the case of Android, it is a mechanism to erase not only the browser but also the cache data recorded in apps, games, etc.
As a result, when you use the apps you normally use immediately after deleting the cache, the amount of communication may increase rapidly.
Therefore, immediately after deletion, we recommend using the app in an environment connected to Wi-Fi.
For Windows/Google Chrome
You can clear the cache of Google Chrome on your Windows PC by following the steps below.
1. Open the menu on the top right (3 dots icon)
2. Select “More tools”
3. Select “Clear browsing history”
4. Set the “Period” dropdown to “All period”
5. Check only “Cached images and files”
6. Click the blue button “Delete data”
If you want to delete your browsing history and cookies as well as your cache, just check the other items when performing step 5.
For Windows/Microsoft Edge
You can clear the cache of Microsoft Edge on your Windows PC by following the steps below.
1. Open “…” in the upper right corner
2. Select “Settings” at the bottom
3. Select “Privacy, Search & Services”
4. Click the white button “Select data to clear”
5. Set the “Time Range” dropdown to “All Periods”
6. Check only “Cached images and files”
7. Click the blue button “Clear now”
Similar to Google Chrome, if you want to delete cookies and browsing history, check these items as well.
For Macintosh (Mac)
There are three ways to clear the cache on Macintosh (Mac): browser, application, and system.
Clear Safari cache
In Safari, you can quickly clear the cache using the shortcut “Command + R” or “Shift + Reload button”, but if you cannot clear it successfully, use the following method to clear it.
1. Launch Safari and click “Safari” from the menu bar
2. Click “Preferences” from the pull-down menu
3. The environment settings screen will be displayed. Click the gear icon “Details” from the top menu.
4. The details screen will be displayed, so check the “Show ‘Development’ menu in menu bar” option at the bottom.
5. When you close the details screen, a menu called “Development” will be added to the top menu bar, so click it.
6. Click “Empty cache” from the pull-down menu to clear Safari’s cache.
Clear Chrome cache
In Chrome, you can quickly clear the cache with the shortcut “Command + R” or “Command + Shift + R”, but if you cannot clear it successfully, use the following method to clear it.
1. Start Chrome and click “Chrome > Preferences” from the menu bar.
2. The settings screen will be displayed, so click “Privacy and Security”
3. The privacy and security screen will be displayed, so click “Delete browsing history data”
4. Check “Cached images and files” and click the “Clear data” icon button to clear Chrome’s cache.
Clear Firefox cache
In Firefox, you can quickly clear the cache with the shortcut “Command + Shift + R”, but if you cannot clear it successfully, use the following method to clear it.
1. Start Firefox and click “Firefox” from the menu bar
2. Click “Preferences” from the pull-down menu
3. The settings screen will be displayed, so click “Privacy and Security”
4. The Privacy and Security screen will be displayed. Click “Clear data…” in the “Cookies and site data” section.
5. A pop-up screen will appear. Check “Web content cache” and click the “Clear” button to clear Firefox’s cache.
Clear application cache
1. Click on “Finder” in the Dock at the bottom of the desktop screen to start it.
2. When “Finder” starts, click “Go” from the top menu bar.
3. Press the Option key while the pull-down menu is displayed
4. “Library” will be displayed, so click it and the “Library” folder will be displayed in “Finder”
5. Find the “Caches” folder and open it.
6. The caches of each application are stored in the “Caches” folder, so hover your mouse over the folder you want to clear the cache and right-click.
7. Click “Move to Trash” from the pull-down menu to clear the cache of the application.
Clear system cache
1. Click on “Finder” in the Dock at the bottom of the desktop screen to start it.
2. When “Finder” starts, click “Go” from the top menu bar.
3. Click “Move to Folder” from the pull-down menu
4. A pop-up screen will appear; enter “/Library/Caches/” in the search box.
5. Select “Library > Caches” from the list of candidates and press the “Enter” key to display the “Caches” folder in “Finder”
6. The cache of each system is stored here, so hover your mouse over the folder you want to clear the cache and right-click.
7. Click “Move to Trash” from the pull-down menu to clear the cache for the system in question (deleting some system caches may cause system problems, so we recommend that you do not delete them unless you are sure. )
Points to note when deleting cache
Most of the cache becomes junk data over time, so deleting it regularly can help keep your system running smoothly.
However, deleting the cache may cause problems, so please keep the following points in mind when deleting it.
stop the application
Before deleting the cache, first make sure you have stopped the application. Especially on smartphones, the application may become unstable the next time it is started, so it is recommended to force stop the application and then delete the cache.
Content that has expired will no longer be displayed
Especially on LINE, such incidents may be reported, so you should check carefully before deleting your cache.
LINE advises that deleting the cache will not delete past chat history or content, but some content, such as videos and images that have never been opened, may no longer be displayed. .
We recommend that you take precautions such as taking a backup before deleting the cache while keeping these incidents in mind.
Web page display speed may decrease
Cache has the role of storing information about web pages that a user has visited once in the browser, and when the user visits again, the information is quickly read from the cache and reflected on the web page.
In other words, caching allows web pages to be displayed faster. If you delete the cache, all the information on the web page will need to be read from scratch, which may slow down the web page display speed.
Data traffic may increase
Due to the events explained above, data traffic may also increase. Content data such as images that were saved in the cache will need to be downloaded and read from the server again, which will likely increase data traffic.
If the image data is light, it will only require a slight increase, but if the image data is heavy, it may lead to an increase in communication traffic.
summary
A summary of the cache mechanism and points is as follows.
Although it is a very convenient mechanism, it also has some disadvantages, so be sure to clear it regularly to maintain comfortable operation.