What is the difference between server and browser cache?

Keep calm and cache. This is the difference between server and browser cache.


Earlier this year, we detailed all the things you need to know about browser cache: What is it? What does it do? And why would you want to clear it?

This time, we’re going to be talking about the difference between browser cache and server cache. These two are often the culprit of confusion and frustration when working on website development projects and performing website updates.

A cache is…

Pronounced “kash” for the computer programmers of the 80’s and “kaysh” for the new wave of developers, a cache is a digital filing cabinet (although not as clunky) where temporary data, including images, webpage styling and text, is stored to deliver the information quicker next time it’s requested.

Using a cache on a website and web browser helps to improve performance such as load time, and assists in creating a better user experience. Yet, with all benefits of using a cache, there’s a small downside which can create issues for users. These issues can be found in both the browser cache and the server cache, so it’s necessary to be aware of how they work, especially if your business regularly releases time-sensitive information.

Understanding server cache

Assembling all the text, images, video, fonts and other graphical effects that go into any web page takes server processing resources, and the more complicated the site, the heavier the resource cost. To save resources when multiple people are visiting a popular site, the server keeps pre-assembled versions of these pages ready, known as a cached version. Cached versions are delivered to the user more quickly, but the version of the page being sent to the user may not always be the most recent.

Defining browser cache

Browser cache works similarly to a server cache, the only difference is that the data is stored on the user’s hard drive. The benefit of this for the user is that their browser doesn’t need to download certain elements of the web page every time they visit.

An example of the kind of data that would be pulled from a website could be a logo, which appears in the same place on every web page. Instead of re-downloading that image, the cache simply stores it.

By regularly clearing your browser cache, you are telling your browser to “forget” what the page looks like and force the server to supply the new, updated version of the page.

How long does it take for a server to purge?

A server will naturally purge itself every few hours or days at most. If you’re a blog owner, whose content rarely gets updated once its upload, it may not be necessary to run server purging software. However, if you own a high-traffic ecommerce website, regularly update content, are dealing with “crisis” scenarios such as a bug or incorrect content or time-sensitive information (i.e. a PR campaign or ASX information) it would be wise to have your website developer running software that purges the server cache after a determined time.

iFactory’s team of experienced Brisbane web developers continuously configure, monitor and enhance server caching performance for a variety of our client’s website hosting requirements. Contact iFactory today to find out how our website support plans can help your business.

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