What Is LCP and How to Improve It: A Non-Technical Guide

If you’re just getting into website optimization, terms like Core Web Vitals and Largest Contentful Paint (LCP) may sound technical, but it’s really just a friendly way of measuring how fast your page’s main content shows up for your visitor.

In simple terms, LCP is the point in time when the “largest visible thing” on the screen (a big image, a text block, or video frame) finishes rendering.

Why should you care? Because when the main content appears quickly, your site feels responsive and trustworthy. When it takes too long, people may bounce, leave before they see anything meaningful. And since Google uses this metric (as part of its Core Web Vitals) for ranking and user-experience signals, it matters for both performance and SEO.

Why LCP matters for you and your visitors?

When someone lands on your site, they don’t wait around for hidden scripts or fancy animations. They want to see something useful, perhaps your headline, maybe a banner image, content that tells them, “Yes, you’re in the right place.” LCP tries to capture that “I can finally start reading or interacting” moment.

Here’s why it matters:

• If your LCP is slow (say 4+ seconds), many visitors may think your page is broken or too slow, and leave.
• A fast LCP (ideally under ~2.5s) gives a smoother feel and can positively affect conversion, engagement, bounce rate.
• From an SEO perspective, since Google uses page experience signals, improving LCP can help.

So if you run, for example, a blog, an eCommerce store, or a portfolio site, LCP is worth understanding and improving.

How to measure LCP

You don’t need special software or coding skills to measure LCP. The quickest way is to use PageSpeed Insights – Google’s free tool that checks how your page performs for real users and in simulated tests.

1. Go to PageSpeed Insights.
2. Enter your website URL and click Analyze.
3. Wait a few seconds while it runs both “field data” (real user data from Chrome) and “lab data” (a test it runs right now).

You’ll see a section labeled Largest Contentful Paint (LCP) under Core Web Vitals assessment.

This tells you how long it takes for the main visible part of your page – usually the biggest image, video thumbnail, or headline – to load for a visitor.

After that, you can scroll down the report and click the LCP link to show audits relevant to LCP only.

You can click the listed insights and diagnostics to check recommendations. That’s where your optimization efforts should focus.

Other tools (optional)

If you want to cross-check your results or test under different conditions:

• Chrome DevTools → Lighthouse tab for local testing. Gives LCP time and highlights which element is the LCP.

• WebPageTest.org for detailed performance breakdowns. Lets you test with specific devices, connection speeds, and locations, and shows filmstrips and videos to visually inspect LCP events.

But if you’re just getting started, PageSpeed Insights gives you everything you need – a clear score, simple explanations, and improvement tips.

What typically causes a slow LCP?

When your LCP is low, something is delaying the largest visible element from rendering. Common causes include:

1. Slow server response or backend delays: Delays in generating or delivering the initial HTML due to slow hosting, heavy database queries, or resource-intensive background processes.
2. Large images or media files: Oversized or unoptimized hero images, videos, or background graphics that take too long to download and render.
3. Render-blocking CSS or JavaScript: External stylesheets or scripts that must load before the browser can paint visible elements.
4. Late-loading or dynamically inserted content: Key elements (like hero images or headings) being lazy-loaded or injected by client-side JavaScript after initial page load.
5. Unoptimized fonts or background assets: Fonts or background images that block text rendering or cause layout shifts before the main content appears.
6. Client-side rendering delays: Frameworks or scripts that build content in the browser rather than delivering pre-rendered HTML, slowing the first paint.
7. Third-party scripts: Analytics, ads, or tracking scripts that interfere with rendering or compete for main-thread processing time.
8. Network congestion or poor CDN coverage: Long round-trip times or high latency between the user and the server or CDN edge.

Understanding which of these bottlenecks applies to your page is the first step to diagnosing slow LCP.

FastPixel can help improve LCP by tackling the following bottlenecks above: It optimizes large images and media files (point 2) with automatic compression and serving next-gen WebP, reduces render-blocking CSS and JavaScript (point 3) through minification and critical CSS, and streamlines fonts and background assets (point 5) for faster rendering. Its built-in global CDN (point 8) also lowers latency and improves delivery speed.

How to improve LCP

Now we’re getting to the fun part. Here’s how you can roll up your sleeves (no coding required) and make your site’s LCP better.

The icon next to a heading means FastPixel can help improve that specific area!

Optimize your images and media

If a large hero image or video is your LCP element, make sure it’s optimized: use next-gen formats (like WebP), compress it, size it correctly for mobile, and avoid having it load after everything else.

• Use next-gen formats like WebP or AVIF.
• Compress images while keeping visual quality.
• Set proper dimensions for mobile and desktop instead of loading one oversized file.
• Lazy load below-the-fold images, but keep the hero image loading early (loading="eager").
• For videos, consider using a poster image and delaying playback until user interaction.

Enable caching and use a CDN

A CDN (Content Delivery Network) brings your assets closer to the user. Caching means that once things are fetched, they load faster on repeat visits. Both help reduce the time before content starts showing up.

A CDN (Content Delivery Network) brings your assets closer to users. Caching ensures repeat visits load fast.

• Use a plugin like FastPixel to handle both.
• Make sure object caching (Redis or Memcached) is enabled if your host supports it.
• Double-check that your CDN is serving images and static files correctly, not just scripts.

Reduce render-blocking CSS/JS

If the browser is busy processing big scripts or styles before it can render your main content, that blocks LCP.

• Defer or async non-critical JavaScript.
• Inline critical CSS for the above-the-fold section only.
• Remove unused CSS.

Prioritize loading of the LCP element

If you know which element is going to be the “largest” visible – a hero image, big heading, banner – make sure it starts loading early.

• Consider setting LQIPs (low-quality image placeholders) for smoother perceived load time.
• Add fetchpriority="high" to key images.
• Preload critical fonts and hero image URLs in the <head>.
• Avoid pushing your main content down with lazy-loaded ads or dynamic sections.

Choose a solid hosting environment

Sometimes the delay is not your fault. If the server is overloaded or sharing resources, that slows down everything. A reliable host plus optimized backend matters.

• Avoid shared hosting.
• Pick a host that uses NVMe storage – it’s significantly faster than traditional SSDs, reducing database and file access times.
• Choose a host with fast TTFB and HTTP/2 or HTTP/3 support.
• Check if your plan includes server-level caching.

Use an all-in-one optimization plugin if you’re on WordPress

If your website is on WordPress, you’ve got a great tool called FastPixel in your arsenal. It handles caching, image optimization, built-in CDN, critical CSS, and many other features.

Installing the plugin, picking a preset, and letting it handle many of the heavy-lifting tasks is a smart move, especially if you’re not a developer and want a simple, straightforward, yet powerful solution.

How to know you’ve improved LCP

After making changes, it’s time to confirm whether your efforts actually paid off. Here’s how to check:

Re-run PageSpeed Insights

Run the test again and look at the LCP metric. Ideally, you want it below 2.5 seconds for most visits.

Compare this with your previous results. For example, a drop from 3.8s to 2.1s means you’re moving in the right direction.

Use Chrome DevTools (Performance tab)

Open your site in Chrome, go to DevTools → Performance, hit record, then reload the page.

You’ll see exactly when the largest element (often a hero image or headline) paints. This helps confirm what’s actually contributing to the LCP score and whether your optimizations are working where it matters.

Compare before and after

Document your previous results and changes. Before-and-after comparisons make improvements clear. For example, if your main image’s render time dropped from 3.8s to 1.9s, that’s a real win.

Check real-user (field) data

Lab tests simulate performance, but field data shows what real users experience. If you have access to Google Search Console’s Core Web Vitals report or the Chrome User Experience Report, review how your LCP is trending there.

Watch behavioral metrics

A faster page usually means users stick around longer. Monitor your bounce rate, average engagement time, and conversion rates. If people are scrolling more, interacting more, or buying more, that’s a strong indicator your LCP improvements are being felt.

Common pitfalls and things to watch

• Don’t assume “everything else is fine” once LCP is good. It’s one metric among others (like interactivity, layout shift).
• Mobile devices often have worse LCP because of slower CPUs, weaker networks. Check mobile test results specifically.
• If you use third-party scripts (ads, chat widgets, analytics), they can delay things.
• Lazy-loading above-the-fold content can backfire. If the LCP element is subject to lazy-loading, it might load later than expected.
• Background images added via CSS are often overlooked but can count for LCP – make sure they’re optimized.

Wrap-up

Whether you’re a blogger, small business, freelancer, or agency, understanding LCP gives you a clear way to improve how fast your site feels. A visitor should see meaningful content as early as possible.

Start by measuring your LCP using PageSpeed Insights. See which element is the largest visible one and how long it takes to render. Then apply optimization steps: image stuff, caching, and eliminating render-blocking resources.

If your site runs on WordPress, using FastPixel gives you a powerful solution that handles many of these tasks with minimal fuss.

Once you start seeing your LCP dip under ~2.5 seconds and your visitors stick around longer, you’ll know the work is paying off.

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