Lcp Nextjs Performance Improvement Strategies

Improving the performance of LCP Next.js is crucial for delivering a seamless user experience.

Optimizing images is a great place to start, as it can significantly reduce load times.

According to the article, using image compression tools like TinyPNG or ShortPixel can reduce image file sizes by up to 90%.

Lazy loading is another technique that can help improve performance by delaying the loading of non-essential resources.

By implementing lazy loading, developers can reduce the initial payload size and improve page load times.

Minifying and compressing code is also essential for improving performance.

The article notes that minifying code can reduce file sizes by up to 50%.

Using caching mechanisms, such as Redis or Memcached, can also help improve performance by reducing the number of database queries.

Implementing a content delivery network (CDN) can further improve performance by reducing the distance between users and the server.

LCP is a metric that measures how your web page loads and operates. It looks at the largest web page component that is visible in the viewport to examine how long it takes to load.

To understand LCP, you should seek to understand if you even have an LCP issue, and the extent of any such issue. This involves looking at what real users are experiencing, rather than what a lab-based tool like Lighthouse or local testing shows.

Lab-based tools can give a wealth of information to explain and help you improve LCP, but be aware that lab tests alone may not be entirely representative of what your actual users experience. This is why it's essential to use Real User Monitoring (RUM) tools installed on your site, or the Chrome User Experience Report (CrUX) which collect anonymous data from real Chrome users for millions of websites.

The LCP metric measures the time it takes to induce the largest component on the web page visible in the viewport. This can be a huge content block, video, or picture that takes up the essential real estate on the page.

To measure LCP of real users, you should look at what real users are experiencing, rather than what a lab-based tool shows. This involves using RUM tools or the Chrome User Experience Report (CrUX) to collect anonymous data from real Chrome users.

After you've understood your LCP, you can start optimizing it by prioritizing your resources. This involves setting the fetchpriority attribute to "high" on the resource that's likely to be your page's LCP element.

To understand your LCP metric, you should seek to understand if you even have an LCP issue, and the extent of any such issue. This involves looking at real user data from tools like Real User Monitoring (RUM) or the Chrome User Experience Report (CrUX), as lab-based tools like Lighthouse or local testing may not be entirely representative of what your actual users experience.

CrUX data can be surfaced from RUM tools installed on a site, or by using the Chrome User Experience Report, which collects anonymous data from real Chrome users for millions of websites. This data is more accurate than lab-based tools.

You can also use PageSpeed Insights CrUX supplementary metrics to diagnose LCP issues. These metrics include First Contentful Paint (FCP) and Time to First Byte (TTFB) timings, which can provide valuable insights into LCP.

Here are some key metrics to look at:

By analyzing these metrics, you can identify potential issues with your LCP and take steps to improve it.

Analyzing Performance Metrics is crucial for any website owner or developer. To better understand how to analyze performance metrics, we need to break down the components of LCP (Largest Contentful Paint) and monitor them effectively.

LCP can be measured in various tools, but lab-based tools like Lighthouse or local testing may not accurately represent real-user experiences. To get a true picture, we should look at real-user data from tools like Real User Monitoring (RUM) or the Chrome User Experience Report (CrUX).

To layer field data onto the Performance panel in Chrome DevTools, you can use the Performance panel and show your local LCP experience next to the page or origin's CrUX LCP in the live metrics view.

The timing information for all LCP sub-parts is available in JavaScript through performance APIs like the Largest Contentful Paint API, Navigation Timing API, and Resource Timing API. This allows you to send the timing values to an analytics provider or log them to your developer tools for debugging and optimization.

You can use the performance.measure() method from the User Timing API to add bars to the Timings track in the Chrome DevTools Performance panel, providing a visual representation of the LCP sub-parts. This helps identify what's happening on the page during these timespans.

To compute the percentage of each LCP sub-part of the total LCP time, you can use the following code:

```javascript

performance.measure('LCP', 'start', 'end').then(measurement => {

const totalLCP = measurement.duration;

const lcpSubPart1 = 0.3 * totalLCP; // assuming 30% of LCP time

const lcpSubPart2 = 0.2 * totalLCP; // assuming 20% of LCP time

console.log(`LCP sub-part 1: ${lcpSubPart1}ms (${lcpSubPart1 / totalLCP * 100}%)`);

console.log(`LCP sub-part 2: ${lcpSubPart2}ms (${lcpSubPart2 / totalLCP * 100}%)`);

});

```

This code logs the total time of each LCP sub-part, as well as its percentage of the total LCP time to the console.

Analyzing PageSpeed Insights is a crucial step in optimizing your website's performance. You can use PageSpeed Insights to access CrUX data, which provides real user experiences.

CrUX data is available in the top section of PageSpeed Insights, labeled Discover what your real users are experiencing. This data is more important than lab-based data, which is available in the bottom section labeled Diagnose performance issues.

PageSpeed Insights shows up to four different CrUX data: Mobile data for This URL, Desktop data for This URL, Mobile data for the whole Origin, and Desktop data for the whole Origin. You can toggle these in the controls at the top and top right-hand side of this section.

If a URL doesn't have enough data to be shown at the URL level, but does have data for the origin, PageSpeed Insights will always show the origin data. This can help you understand whether an LCP issue is specific to this page or a more general site-wide issue.

Looking at the four different categories of CrUX data can also show which device types have LCP issues.

To further optimize LCP, you should also use the First Contentful Paint (FCP) and Time to First Byte (TTFB) timings. These metrics can provide valuable insights into LCP and help you identify potential issues.

A high TTFB can make achieving a 2.5 second LCP challenging, or even impossible. It can be due to multiple server redirects, visitors located far away from the nearest site server, visitors on poor network conditions, or an inability to use cached content due to query parameters.

The delta between FCP and other metrics can be very telling. A large delta between TTFB and FCP could indicate that the browser needs to download a lot of render-blocking assets.

CrUX data can be surfaced from Real User Monitoring (RUM) tools installed on a site, or by using the Chrome User Experience Report (CrUX) which collects anonymous data from real Chrome users for millions of websites.

PageSpeed Insights provides access to CrUX data in the top section labeled Discover what your real users are experiencing. More detailed lab-based data is available in the bottom section labeled Diagnose performance issues.

You can toggle between four different CrUX data categories: Mobile data for This URL, Desktop data for This URL, Mobile data for the whole Origin, and Desktop data for the whole Origin.

Looking at the four different categories of CrUX data can help you understand whether an LCP issue is specific to this page, or a more general site-wide issue.

Here are the four different categories of CrUX data:

CrUX data can help you understand whether an LCP issue is specific to this page, or a more general site-wide issue.

Optimal sub-part times are crucial for optimizing your website's performance. The ideal breakdown of LCP sub-parts on a well-optimized page is not a strict rule, but rather a guideline.

The two sub-parts with "delay" in their names - Resource load delay and Element render delay - should ideally be close to zero. This is because they represent time spent waiting for resources to load or render.

The other two sub-parts - Time to first byte and Resource load duration - involve network requests, which inherently take time. These sub-parts should make up the majority of the LCP time, around 40% each.

A good way to think about the breakdown of LCP time is to focus on loading the HTML document and LCP source as quickly as possible. Any time spent waiting for these resources to load is an opportunity to improve.

Here's a breakdown of the typical LCP sub-part times:

Keep in mind that these time breakdowns are only guidelines, and the most important thing is to ensure your LCP times are consistently within 2.5 seconds.

Next.js is a popular framework for building fast and scalable web applications, and optimizing its performance is crucial for a good user experience. Next.js images score well on Cumulative Layout Shift, which means they load quickly and don't cause annoying text movements.

To further improve performance, you should reduce or inline render-blocking stylesheets. This can be done by inlining small stylesheets into the HTML or reducing the size of larger stylesheets. Removing unused CSS, deferring non-critical CSS, and minifying and compressing CSS are all effective ways to reduce stylesheet size.

Inlining scripts is another technique that can help. In cases where JavaScript code needs to run as early as possible, it's best to inline it so rendering isn't delayed waiting on another network request. However, only inline small scripts to avoid impacting subsequent page loads.

Server-side rendering (SSR) is another performance optimization technique that can help. By running client-side application logic on the server and responding with full HTML markup, you can ensure image resources are discoverable from the HTML source and page content can render without additional JavaScript requests.

Here are some specific techniques for reducing resource load delay:

By implementing these performance optimization techniques, you can improve the speed and responsiveness of your Next.js application and provide a better user experience.