Boosting Web Performance: Key Strategies for Faster LCP

Curious how some sites seem to outperform their competitors both in SEO and user experience?

The answer: speed. In the web world, we measure that in one way with a metric called Largest Contentful Paint (LCP).

LCP is the point at which your page’s main content has loaded, and is considered visible.

So what does that really mean?

When your LCP lags, your users will leave. According to recent studies, 53% of mobile visitors leave websites that take over three seconds to load.

That’s more than half of your visitors bouncing before they ever get the chance to see what your company has to offer them.

But there’s good news. Mastering how to improve LCP isn’t difficult, or out of reach for web developers.

With a few tweaks and an understanding of where to focus your optimization, any developer can rapidly boost their LCP results.

So let’s dig in…

What you’re about to discover:

1. What Is LCP And Why Does It Matter?
2. The Main Causes Of Slow LCP
3. 6 Strategies To Improve LCP Today
4. How To Measure Your Progress

What Is LCP And Why Does It Matter?

The largest contentful paint (LCP) measures the amount of time it takes for the main content of a page to load.

This could be an image, video, or block of text.

Whatever the main piece is above the fold, that is what the LCP tracks.

Anything under two and a half seconds is considered “good” by Google.

Between 2.5 and 4 seconds is in the “needs improvement” category, and anything above 4 is a “problem.”

LCP affects search rankings, because Google is taking Core Web Vitals (CWV) and adding them as direct ranking signals.

Sites with better Core Web Vitals get preference in Google SERP results.

Your LCP score has real-life business impact. LCP directly correlates to search rankings, which drive traffic.

Google’s statistics back up this trend, too. Research from Portent found that sites loading in 1 second have conversion rates 3x higher than sites that load in 5 seconds.

Even by Google’s standards, that’s a massive difference. There’s a huge gap between surviving and thriving online. LCP optimization is the thing separating those two groups.

The Main Causes Of Slow LCP

Before web developers can remedy LCP, they have to understand why it’s slow.

There are four primary reasons:

• Slow server response times: The server takes too long to deliver the first byte of data
• Render-blocking resources: CSS and JavaScript files that must load before the page can be rendered
• Large resource load times: Images and video files that are too big or not compressed
• Client-side rendering issues: JavaScript code that must be executed before the content can appear

The majority of low-scoring LCP performance can be attributed to one or more of these issues.

The key is narrowing down the problem areas, so that the fixes become clear.

6 Strategies To Improve LCP Today

These are the strategies that work.

These are not internet hacks, or web development myths that have been passed down for years.

These are time-tested, scientifically proven ways of improving LCP.

Let’s go over each method.

Optimize Your Server Response Time

Everything begins at the server. If the server is slow to respond, the rest of the page cannot load at all.

Try these quick tips:

• Use a CDN, so that content is served from a location geographically closer to the visitor
• Implement server-side caching
• Upgrade to a better hosting provider if necessary
• Optimize database queries, so that page rendering is not bogged down by them

Time to first byte (TTFB) should be under 200ms. Anything longer and the LCP will drop.

Eliminate Render-Blocking Resources

CSS and JavaScript are both render-blocking.

They’re files that the browser must download and process before it can render anything on the page.

When these are present, it makes it impossible for the page to load the LCP within the ideal time period.

To fix this:

• Inline critical CSS directly in the HTML head element
• Defer non-critical JavaScript using defer and async attributes
• Remove unused CSS and JavaScript from the page entirely
• Minify all CSS and JavaScript

For every millisecond of render-blocking code that can be removed, LCP will go down by a millisecond.

Optimize Images Properly

Images are usually the largest piece of content on the page.

So the image is often the LCP, and that means that optimizing images is one of the quickest ways to improve LCP.

Essential image optimizations are:

• Compress images without degrading visible quality
• Use modern formats like WebP and AVIF
• Implement lazy loading for all images below the fold
• Specify image dimensions so layout shifts aren’t introduced
• Use responsive images that always serve the correct size for the user

LCP image should load as soon as possible. Preload it in the HTML head with <link rel=”preload”>.

Prioritize The LCP Element

The browser isn’t aware of what the most important element is.

It’s the developer’s responsibility to make that clear. By prioritizing the LCP element, the load time will improve drastically.

Here’s how:

• Preload the LCP resource in the document head
• Don’t lazy load the LCP element
• Use fetchpriority=”high” on the LCP image
• Ensure the LCP element is part of the initial HTML response (not injected via JavaScript)

This alone can take hundreds of milliseconds off LCP.

Reduce JavaScript Execution Time

JavaScript is evil. No, not really. Too much JavaScript will bog down page load times.

JavaScript is a huge culprit. Large JavaScript bundles take time to download, parse, and execute. Everything on the page must wait until the JS is done.

Fix it with these methods:

• Code-split JS so that only the necessary code is downloaded and executed
• Remove unused third-party scripts
• Defer any non-essential JavaScript until after LCP is measured
• Move heavy calculations to web workers

Everything that’s not JavaScript should be considered for removal, until it’s proven that it’s actually helping the user.

Use A Performance Budget

A performance budget is the setting of limits.

It’s forcing certain resource types to be a maximum size, so that LCP doesn’t slowly creep back up to “poor” over time.

Performance budgets are the best way to make the entire team responsible for maintaining site speed.

Set budgets for:

• Total page size
• Individual image dimensions
• JavaScript bundle sizes
• HTTP request numbers

Automated tools will alert developers when these budgets are exceeded. This means problems are solved in development, not post-launch.

How To Measure Your Progress

Optimizing LCP is a wasted effort unless it’s being measured.

Google provides a handful of free tools for this:

• PageSpeed Insights for quick checks
• Lighthouse in Chrome DevTools for in-depth audits
• Search Console Core Web Vitals report for overall site analysis
• Measure often. Test regularly. Keep track of changes over time, because LCP optimization never really ends.

Here’s The Bottom Line

Optimizing LCP is no longer an afterthought.

Google is using it for ranking signals. Users expect a snappy experience. Slow sites lose out on traffic, and conversions.

In summary:

• Optimize server response times first and foremost
• Eliminate render-blocking CSS and JavaScript
• Compress and format images
• Prioritize the LCP element with preload
• Reduce JavaScript execution time
• Set performance budgets to hold yourself accountable

Focus on the low hanging fruit, and test. Rinse. Repeat.

Speed is the name of the game on the internet, so make sure LCP is one of your top priorities.

You’ll see the payoff in all your metrics, not just LCP.