What is browser cache?

Browser cache is an important technology that improves the performance of websites and applications. Browser cache reduces network traffic and latency by reusing previously fetched resources. In this article, we will learn about the concept, types, caching policies, validation, and pros and cons of browser cache.

Browser cache concept

Browser cache is a private cache used by web browsers. A private cache is a cache that is used exclusively by a single user and is stored on the user's computer or mobile device. Browser cache stores the resources of the web pages that the user visits and reuses them when they visit again.

For example, images, style sheets, JavaScript files, etc. can be stored in the browser cache. This way, you can reduce network requests and shorten the time required to display resources.

Browser cache types

There are several types of browser cache. The most common ones are memory cache and disk cache.

Memory cache is a temporary cache that is stored in the computer's RAM. Memory cache can be accessed quickly, but it has limited capacity and is deleted when the browser is closed.

Disk cache is a permanent cache that is stored on the computer's hard disk. Disk cache has a large capacity and persists even when the browser is closed, but it has slow access speed.

Typically, browsers use a mix of memory cache and disk cache. For example, there are sessionStorage and localStorage.

Browser caching policy

Browser caching policy determines how long to store and when to revalidate resources between the server and the client. Browser caching policy is delivered through HTTP headers.

The most important header is the Cache-Control header. The Cache-Control header is used to specify directives for the caching mechanism for both requests and responses.

For example, the max-age directive specifies the maximum time that the resource is considered valid, and the no-cache directive forces the request to be sent to the origin server before using the cached copy.

Browser caching pros and cons

Browser caching provides many benefits, but also has drawbacks. The advantages of browser caching are as follows:

• It improves the performance of websites and applications. It reduces network requests and latency, thereby shortening the time required to display resources.
• It reduces network costs. It reduces network costs by reducing network requests and data transfer.
• It supports offline mode. You can use cached resources even when the network connection is disconnected.

The disadvantages of browser caching are as follows:

• It can show outdated information. If the resources provided by the website change frequently, the cached resources may not reflect the latest information. In this case, the user may not get the latest information.
• It can cause security issues. If the user visits a page that contains personal information while logged in, and that page is stored in a shared cache, other users may be able to see that page. To prevent these problems, you need to perform appropriate caching policies and validation.

Conclusion

Browser caching is an essential technology for web performance optimization. Browser caching improves the performance of websites and applications by reusing previously fetched resources. However, browser caching has pros and cons, so you need to solve the problems through appropriate caching policies and validation.