Table of Contents

Cached Websites

What is website caching?

Types of Website Caching

Browser Caching

Server Caching

External Caching

What is core web vitals?

Largest Contentful Paint LCP

First Input Display FID

Cumulative Layout Shift CLS

Conclusion

Cached Websites

Cached websites improve the user experience and reduce page load times. When a user visits a website, their web browser downloads and stores a copy of the website's files, including HTML pages, images, scripts, and other resources, on their local device, e.g. phone, tablet or laptop. This cached copy can then be accessed quickly and efficiently the next time the user visits the same website.

Caching websites provides several benefits for both website owners and users. For website owners, it can reduce server load, bandwidth usage, and hosting costs, as the cached version of the website can be served directly from the user's local device instead of being reloaded from the server. For users, it can significantly improve page load times and reduce data usage, especially on slower connections or mobile devices.

Cached websites can also be useful in situations where internet connectivity is limited or intermittent, such as in remote areas or during natural disasters, where users may not be able to access websites in real-time. In such cases, a cached version of the website can be accessed from the user's local device, providing access to important information and services. Websites can also be cached on an external network called a content distributed network (CDN) with data centers located around the world. This allows cached data to be served from a location closest to the user requesting the content.

However, it's important to note that caching websites can also have some drawbacks, such as serving outdated or inaccurate information, which can negatively impact the user experience. Website owners need to be aware of these potential issues and implement appropriate measures, such as cache purging and cache expiration time stamps, to ensure that the cached version of their website is always up-to-date and accurate.

What is website caching?

Website caching refers to the process of storing website data temporarily in a cache, which is a hardware or software component that stores frequently accessed information for faster retrieval. When a user visits a website, their browser sends a request to the server for the website's content, which includes HTML files, images, scripts, and other resources. If the server has previously cached the requested content, it can serve it directly from the cache, rather than fetching it again from the original source.

Caching can speed up website performance by reducing the time it takes to fetch and deliver content to the user's browser, improving page load times and reducing server load. Caching can be implemented in several ways, including using browser caching, server caching, and content delivery networks (CDNs).

Overall, website caching can improve the user experience by making websites load faster and more efficiently, and it can also reduce the load on servers, making websites more scalable and cost-effective.

Types of website caching

Browser caching

This type of caching is performed by the user's web browser and involves storing static resources, such as images, stylesheets, and JavaScript files, on the user's computer. This caching can be implemented by setting cache-control headers in the server's response.

Server caching

This type of caching is performed by the web server and involves caching the entire response for a given URL. This can be implemented using tools like Varnish or Nginx.

Types of server caching

• Memcached - An object caching system used to store data in memory.
• Redis - An object caching system used to store data in memory.
• Varnish - An HTTP reverse proxy and cache used to speed up websites.
• APCu - A PHP opcode caching system used to store compiled PHP code in memory.
• Nginx FastCGI cache - A caching mechanism used by Nginx to speed up dynamic content.
• Squid - A caching proxy used to improve web server performance.
• LiteSpeed Cache - A caching plugin used to speed up WordPress and other web applications.
• mod_cache - An Apache module used to cache frequently used web pages.
• CacheControl - An Apache module that provides advanced caching directives.
• FCGI Cache - An Apache module used to cache frequently used FastCGI responses.

External caching

Contet Delivery Network (CDN)

What is a content delivery network (CDN)?

A CDN (Content Delivery Network) is a network of servers distributed across the world that work together to deliver website content, such as HTML pages, images, videos, and other files, to users based on their geographic location. When a user requests a file from a website, the CDN's server closest to the user's location delivers the file, resulting in faster load times and a better user experience.

CDNs work by caching website content on their servers, so that the content can be quickly delivered to users without having to make long-distance server requests back to the origin server. They also use various optimization techniques, such as compression and minification, to reduce the size of the files being delivered, further improving load times.

Using a CDN can provide many benefits, including:

• Faster page load times: By delivering content from a server closer to the user, a CDN can significantly reduce the time it takes for a page to load.
• Improved user experience: A faster page load time can improve the user experience and reduce bounce rates.
• Improved scalability: CDNs can handle large amounts of traffic, improving the scalability of a website.
• Improved security: Some CDNs, e.g. Cloudflare, AWS Cloudfront and Bunny CDN, also offer security features, such as DDoS protection and SSL/TLS encryption, to protect websites from cyberattacks.
• Improved search engine rankings: Faster page load times and improved user experience can lead to better search engine rankings.

CDNs are particularly useful for websites with a global audience, large media files, and high traffic volumes. However, they can also be useful for smaller websites that want to provide a better user experience and improve their search engine rankings.

Benefits of website caching

• • Improved website performance
  • Reduced server load

What is Core Web Vitals?

Core Web Vitals is a set of specific, user-centered metrics that Google uses to measure the quality of a website's user experience. These metrics are focused on three key aspects of the user experience: loading, interactivity, and visual stability. The Core Web Vitals metrics were confirmed as a ranking factor in Google search, in 2021.

The three Core Web Vitals metrics are:

Largest Contentful Paint (LCP): This measures loading performance and reports the render time of the largest image or text block visible within the viewport. An LCP score of less than 2.5 seconds is considered good.

First Input Delay (FID): This measures interactivity and reports the time it takes for the website to respond to the first user input, such as a click or tap. An FID score of less than 100 milliseconds is considered good.

Cumulative Layout Shift (CLS): This measures visual stability and reports the amount of unexpected layout shift that occurs during the loading process. An CLS score of less than 0.1 is considered good.

By focusing on these specific metrics, website owners and developers can make targeted improvements to their site's user experience, which can lead to better search rankings and a more satisfied audience. Google's PageSpeed Insights tool and other web performance analysis tools, e.g. webpagetest.org, gtmetrix.com, debugbear.com, pingdom.com and others, can help you measure and optimize your site's Core Web Vitals metrics.

Largest Contentful Paint (LCP)

How to optimize LCP

Optimizing Largest Contentful Paint (LCP) involves reducing the time it takes for the largest content element on your page to load and render in the user's browser. Here are some tips for optimizing LCP:

• Optimize your images: Large, unoptimized images can significantly slow down your site's load time. Use compressed images and serve them in next-gen formats like WebP, JPEG 2000, and JPEG XR. Also, consider using responsive images to serve the appropriate image size based on the device being used.
• Minimize render-blocking resources: Render-blocking resources such as CSS and JavaScript files can slow down the rendering of your page's largest content element. Use asynchronous loading or defer loading of such resources to allow the largest content element to be rendered faster.
• Use a content delivery network (CDN): A CDN can distribute your site's content across multiple servers located around the world, allowing users to access your site's content from a server that is physically closer to them. This can help reduce the load time of the largest content element.
• Reduce server response time: A slow server response time can significantly slow down your site's load time. Optimize your server response time by using a fast web hosting service, using caching and compression techniques, and minimizing database queries.
• Prioritize above-the-fold content: By prioritizing above-the-fold content, you can ensure that the largest content element is loaded and rendered before other elements further down the page. This can help reduce the perceived load time of the page.

By implementing these optimization techniques, you can improve your site's LCP score and provide a better user experience for your audience.

First Input Delay (FID)

How to optimize FID

Optimizing First Input Delay (FID) involves reducing the time it takes for your website to respond to the user's first input, such as a click or tap. Here are some tips for optimizing FID:

• Reduce JavaScript execution time: Long JavaScript execution times can delay the response to the user's input. Use code splitting and lazy loading techniques to reduce the amount of JavaScript that needs to be executed when the page loads.
• Minimize main thread work: Main thread work, such as rendering and layout, can also delay the response to the user's input. Use CSS Grid or Flexbox instead of table-based layouts, optimize your CSS, and avoid expensive layout calculations to minimize main thread work.
• Optimize third-party scripts: Third-party scripts, such as advertising scripts, can significantly delay the response to the user's input. Use asynchronous loading or defer loading of third-party scripts to reduce their impact on your site's performance.
• Use a faster web hosting service: A faster web hosting service can improve your site's response time, which can improve your FID score.
• Use a browser cache: A browser cache can store frequently accessed files on the user's device, allowing them to be quickly retrieved when needed. This can help reduce the load time of your site's resources and improve FID.

By implementing these optimization techniques, you can improve your site's FID score and provide a better user experience for your audience.

Cumulative Layout Shift (CLS)

How to optimize CLS

Optimizing Cumulative Layout Shift (CLS) involves reducing the amount of unexpected layout shift that occurs during the loading process. Here are some tips for optimizing CLS:

• Set size attributes for images and videos: Setting the width and height attributes for images and videos can ensure that the browser reserves the appropriate amount of space for them, reducing the likelihood of layout shifts.
• Reserve space for ads and embeds: If you use advertising or embedded content on your site, make sure to reserve space for them to prevent layout shifts when they load.
• Use animations and transitions wisely: Animations and transitions can add visual interest to your site, but they can also cause layout shifts if not used correctly. Use CSS animations or transitions that don't change the layout of the page, or use the Web Animations API to control the animation or transition directly.
• Load web fonts properly: Loading web fonts can also cause layout shifts if not done properly. Use a web font loading strategy that ensures that the text doesn't change size or layout when the fonts load.
• Prioritize content loading: Prioritize the loading of above-the-fold content to ensure that users see the most important content first. You can use the loading attribute to defer the loading of non-critical content, or use lazy loading techniques to load content as it becomes visible on the screen.

By implementing these optimization techniques, you can reduce the amount of unexpected layout shift on your site and improve your CLS score.

Conclusion

By understanding the various types of website caching and how it affects core web vitals, we can optimize our web server for maximum performance, higher core web vitals scores and an optimized user experience.

Website caching can have a significant impact on core web vitals metrics, particularly on First Contentful Paint (FCP) and Largest Contentful Paint (LCP), by reducing the time it takes for the browser to load and render a web page. Caching involves temporarily storing web page resources, such as HTML, CSS, JavaScript, and images, on the user's device or on intermediate servers, allowing them to be quickly retrieved when needed. By serving cached resources, you can significantly reduce the load time of your web pages, resulting in faster FCP and LCP times and better Core Web Vitals scores.

By improving Core Web Vitals metrics, you can provide a better user experience, which can result in increased user engagement, higher conversion rates, and ultimately, better search engine rankings. Google has announced that Core Web Vitals will become a ranking factor in 2021, which means that sites that perform well on these metrics may be given a boost in the search engine results pages. Additionally, faster page load times can lead to better crawl efficiency, as search engine bots can crawl more pages within a given time frame.

To leverage website caching to improve Core Web Vitals and search engine rankings, implement a caching strategy that takes into account browser caching, server caching, and external caching (CDN).