What is Caching?
A cache is a place (software or hardware) where data is stored temporarily to quicken access to it. Likewise, the process of storing data for quick retrieval is called caching.
You can take the cache as a middle point between the end user (who sends a request for particular information) and the main memory. This middle point has a short-term memory and a limited space to store data.
Caching can be discussed in different contexts, such as in the context of devices (tablets, smartphones, laptops). Likewise, apps (YouTube, Snapchat, etc.) have their own cache to fetch data quickly without going back to the main memory every time.
Apart from them, there are four major types of caches through which we can describe the caching process.
Types of Cache
The four main types of caches are:
Browser Cache
Browser cache is a type of client-side cache, which means the caching is done on the end user’s side.
When a user visits a webpage for the first time on the internet, the web browser has to download many pieces of information to display the required results.
These pieces of information include resources, such as images, HTML files, CSS files, JavaScript files, etc. These resources must be retrieved from the web server.
This process is not repeated every time a user visits that website or webpage because now this information will be taken from the browser cache stored on the user's device.
This storage is the cache, which is basically stored on the hard drive of the device (i.e., computer) a user is using.
When a page is modified, the older version becomes useless, and the browser replaces it with a new version.
This process of replacement is done when the user removes the cache or when the browser updates the cached content automatically.
Server Cache
In server caching, data is stored in a server cache. This server cache can be implemented through a proxy server. Proxy servers act on behalf of the origin servers to reduce the distance between the end user and the origin servers.
Proxy servers not only send requests to the origin server and deliver responses to the client (one who sends the request) but also store data in the form of images, videos, webpages, etc.
Website Cache
Website cache is a type of cache used to store website data for faster delivery to users.
The web server or database server has persistent memory from which a copy of data is retrieved and stored in a site’s cache on a temporary basis so that the time required to deliver content to users is reduced.
This way, caching (or the process of storing data) enables a browser to display information regarding a particular website faster.
Website caching allows webpages, HTML files, images, JavaScript files, etc., to be stored for later retrieval requests.
In the case of site caching, you will see the fresh version of pages that change frequently when the cache is updated or refreshed. While the data that is not yet updated will be fetched from the site’s cache.
Search Engine Cache
Another type of cache relates to search engines (more importantly, Google), which crawl and save snapshots of crawled pages on their servers.
It is a bit different from other types of cache because the cached pages of search engines are primarily used for crawling and indexing purposes. In daily browsing, you will see live web pages most of the time.
In addition to Google, Bing, Yandex, and Baidu also cache pages while crawling.
Why is Caching Important?
Caching reduces the time it takes to retrieve data by temporarily storing frequently accessed data closer to the end user, either on the client side or the server side.
This enables the user to quickly access the data without having to go all the way back to the original source every time.
Caching is especially important in high-traffic situations where multiple users are accessing the same data simultaneously, as it can help to reduce the overall load on the system and improve the speed and reliability of data transfer.
Which Types of Caching Play a Role in SEO?
Two types of caching can play a critical role in SEO:
Website caching
Search engine caching
Website Caching
From the SEO point of view, website caching helps improve the optimization of pages.
Less Load Time, More Crawling
Page load time is the time a page takes to display the full content of the page. When a page is readily available that a user is searching for, it will consume less time to load.
On the other hand, if the same page’s content has to be downloaded repeatedly, it would slow down the loading time.
This way, the page load time affects crawling as Google crawls fewer pages on a website that take more time to load.
Caching can help to reduce page load time by storing frequently accessed resources closer to the end user, which will indirectly increase the optimization of web pages.
Better User Experience, More Traffic
Caching can improve the user experience and increase your page's traffic. It is because a user cannot wait for a long time while the page is loading.
The more time your web pages take to load, the fewer users will visit your web pages. It is natural for a visitor to click and stay on a page that loads quickly.
More Conversions, More Growth
As a result of all these benefits, you can get higher conversion rates when users respond to your page’s call to action. It will result in improved growth of your business.
Search Engine Caching
Search engine caching can also play a crucial role in optimization.
Retrieve Old Content
If your website has gone through a problem, in that case, there is a possibility of losing the data; you can use a cached version of the pages.
You will find web pages’ content in the form of a cached backup. While not all of the data may be available in the cached version, it can still provide a significant amount of information that can be retrieved.
This can be especially helpful in situations where data loss has occurred or when a website is experiencing downtime or technical issues.
See Crawled Pages
If you have updated a page on your website, you can check if it has been crawled by looking at the cached version.
However, it is possible that the updated version may not be immediately visible in the cached version. This is not a cause for concern, as the updated version can still be indexed by search engines.
How Does Google Caching Work?
When Google crawls pages of a website, it saves copies of all these pages in the backup to retrieve them if the web page is unavailable for some reason.
The copy of a page that Google stores in the cache will be the latest cached copy of that webpage.
It can be called server-side caching because the snapshot or the copy will be saved on the server.
When a user visits a webpage on Google, they will not typically view the cached version of the page. Instead, they will view the live version of the page as it exists on the website's server.
Drawbacks of Caching
The Problem of Low Storage Space
Caching involves storing copies of data or files to provide quicker access when requested by the system or user.
However, as more data gets cached, it can consume a significant amount of storage space on your device or server.
When the storage space becomes low, it can negatively impact the overall system performance, forcing you to clear the cache to free up space and maintain normal operation.
The Corrupted Cache can Affect the System
A cache can sometimes become corrupted due to software bugs, hardware failures, or other unexpected issues.
When this occurs, the data stored in the cache may be lost or become inaccessible, causing disruptions in your system's functionality.
Resolving a corrupted cache can be time-consuming, and until the issue is fixed, your system may not perform optimally.
Caching FAQs
Why Does Google Cache a Page?
Google keeps the pages in storage after crawling them because there can be an error in the page loading, or the webmaster may modify it, which is temporarily unavailable.
In such cases, a user can be presented with a cached version rather than a live webpage.
Sometimes, the website’s speed is slow, or it is down for some reason. In this case, you can visit cached pages.
Can I Prevent Google from Page Caching?
You can prevent Google from caching your page by adding a tag in the HTML code. You may want to do this when you are going to update the page soon. In that case, you can use meta tags to help you with this.
In the <head> section of a specific page, you can add the following code:
<Meta Name="GoogleBots" Content="Noarchive">This tag will instruct Google not to cache that specific page only. You can do the same with every page you want not to be cached.
Do All the Crawled Pages get Cached?
It is a misconception that all the pages that Google crawls are cached. According to John Mueller’s Twitter reply:
“We don't cache all pages that we index, so that can happen. Sometimes it takes a while, sometimes we just don't cache it at all.”
Can I Remove Cached Pages?
You can remove cached pages using Google Search Console. If you have your site verified by Google Search Console, then you can simply sign in to your account:
In a list of options to the right, you should click “index”, choose “Removal”, then “temporary removal”.
If you click “new removal” in “temporarily remove URL”, a bar will be displayed where you can type your URL.
Selecting “remove this URL only” will remove a specified URL, while selecting “remove all URLs with this prefix” will remove an entire folder.
If you choose “temporary removal”, the current snippet and cached version will be removed for a period of six months. After this period, they will crawl and cache again.
Choosing “clear cached URL” will remove cached pages only, while the original page will remain live.
What Can Google’s Cached Pages Indicate?
Page’s Slow Speed
If the search results show the cached version of your page, it means your page has a slow loading speed. You can work on the errors that are responsible for this.
A Competitor’s Similar Content
By looking at the cached and fresh versions of your competitor’s pages, you can assume your competitor's changes to the page.
Ending Note
Caching is an essential process that temporarily stores data to speed up access and improve user experience. Various types of caches exist, such as browser, server, website, and search engine caching.
While caching can enhance SEO and website performance, it can also present drawbacks like low storage space, corrupted cache, and security risks.