Largest Contentful Paint – What is it & why is it important for SEO?

In today’s digital world people are used to being able to work, shop, communicate and get access to information from almost anywhere, at any time. This fast-paced culture, while very beneficial, also means that most individuals aren’t used to having to wait for results and when they’re browsing online, slow-loading webpages just won’t cut it. In fact, a significant 40% of users say they’ll abandon a webpage that takes more than three seconds to load, with almost half (47%) of consumers revealing they expect a webpage to load in two seconds or less.

This is why page speed has become such an important metric to businesses in recent years, with emphasis being placed on loading speeds and user experience. There are a number of metrics that already exist for measuring page speeds including Load Event, First Paint (FP), First Meaningful Paint (FMP) and DOMContentLoaded (DCL). These are just some of the popular metrics used and there are a handful of others you may have already heard of.

While all of these have their uses, they are by no means flawless. Some don’t address user experience and others can’t accurately measure page speed on a large scale, which is no good if you’re looking for specific, accurate results. Because of this, Google wanted to find a new way to measure page speeds and performance that lead to more accurate reporting. This is where Largest Contentful Paint (LCP) comes in.

Instead of trying to invent some complicated algorithm that no one can fully understand, the team at Google decided to create a more basic solution that would give the best results. This metric is called Largest Contentful Paint (LCP). In this guide, we’re going to take a closer look at what LCP actually is, why it is so important for SEO and therefore why your business should care about it. We’ll also look at ways you can optimise your webpages for better LCP and therefore better loading speeds.

What is Largest Contentful Paint?

According to research from Google, it’s fair to assume that the most essential element of the page is the largest one visible in the viewport. This is typically an image, video or perhaps a block of text. This is why Google has come up with the LCP metric. Largest Contentful Paint measures how long it takes for the largest content element in the viewport to become visible to the user, determining when the main content has actually finished rendering on the page.

This is a new metric that falls into their Lighthouse performance report. But why did Google feel the need to create something new? Well, LCP does something that the other metrics can’t. By marking the point at which the primary content is visible, the tool helps to identify how fast content appears to visitors, in relation to them actually seeing the content they want, not just the point in which the page has started loading. So in a nutshell, LCP gives you a more accurate understanding of how fast content is loading and is visible to human visitors.

For example, while other metrics like First Contentful Paint (FCP) capture the moment the page starts to load, this doesn’t mean the content has appeared on the visitor’s screen. So though it may only take 1.2 seconds for a page to begin loading, the key information, images or videos may not actually be visible to the user for another 4-5 seconds. Meaning the loading speed is actually a lot slower than first thought.

But by using this new metric, web developers are able to understand exactly how quickly a visitor sees the most important and relevant content and they can therefore adjust and optimise their webpages accordingly. It is estimated that an LCP score of 2.5 seconds or less is considered good, anything longer than that may require some more work. According to Google’s definition of Largest Contentful Paint, ‘a fast LCP helps reassure the user that the page is useful’.

Why is Largest Contentful Paint important for SEO?

Now we have a better understanding of Largest Contentful Paint and what this metric does, we can look at why this is so important for SEO. It is widely recognised amongst the SEO community that site speed can be a contributing factor towards rankings, but there are a number of reasons for this and as a result, a number of reasons why LCP will impact SEO.

Below, we’ll look at five reasons a good LCP is important for SEO and for making your webpages more visible to your target audience.

1. It is a metric of Google’s own invention

Of course, there are other search engines besides Google, but as this is one of the most globally recognised engines, it’s usually the one businesses hope to target first. Not to mention the fact that many other search engines tend to follow by Google’s example when it comes to new features and algorithms for SEO, so it always pays to listen to the experts.

Since Largest Contentful Paint is a metric of Google’s own invention, it would be crazy for them to just ignore it – and for you to do the same! After all, it will become part of the Chrome browser used by more than 310 million people globally (figures from 2012). Because of this, it is expected that LCP will become one of the default factors Google uses when measuring a website’s performance. This will then directly impact how well webpages rank on its search engine results pages (SERPs).

2. Site speed affects rankings

When it comes to SEO, Google has often emphasised the importance of web performance, particularly when it comes to mobile. It has also indicated on more than one occasion that site speed is an important part of this web performance and is one of the signals that the search engine’s algorithm uses to rank webpages.

Not only this, but pages with longer load time tend to have higher bounce rates. As we’ve mentioned above, a large number of people will abandon a webpage after three seconds if it has not loaded. Higher bounce rates can lead to lower conversion rates, this in turn can have a negative impact on your visibility in the SERPs.

What has this got to do with LCP? With Google now using LCP to measure how long it takes for content to appear on the screen rather than simply begin to load, some pages might actually appear faster or slower than first thought. This can then impact how well they rank on Google. So it’s clear that site speed is important and getting your LCP below 2.5 seconds should be a priority for developers and website owners.

3. Slow loading affects crawling

Using LCP reporting, you can get a more accurate understanding of the load time of your webpages. This can highlight any areas that need improving in order to reduce your LCP. This is crucial because slow page speeds limit the number of your webpages a search engine can crawl at one time, which can then impact your indexation. This will have a direct effect on how well your site ranks in SERPs.

4. User experience is an important ranking factor for SEO

Page speed is important to the visitor, it impacts the experience they have on your site. It sounds a bit silly, but Google currently has algorithms in place that attempt to rank your webpages on delightfulness. Essentially, they’re looking at how enjoyable the experience of browsing your website and webpages is to visitors. After all, they don’t want to put webpages at the top of their search results if they are slow loading and difficult to navigate.

What has this got to do with LCP? Well aside from the obvious fact that quicker page loading times means a better experience for visitors, Largest Contentful Paint will now be a direct contributing factor towards determining how ‘delightful’ your website is and whether visitors will have a good time visiting your pages. Not only this, but those who have a better experience on your webpages will be more likely to convert. So getting a strong LCP is a win-win really!

5. Content is key to visitors

One thing that the LCP metric does that others don’t, is it places experience with content at the forefront of user experience. A huge part of SEO and ranking well has always been presenting relevant content that is useful to the visitor. This is what helps to increase your domain authority and shows the search engine that you’re a helpful and reputable source that deserves to rank higher on SERPs.

Because Largest Contentful Paint is all about the loading time of the primary content on the page, a good user experience is no longer just about offering useful content, but also ensuring that visitors have a good experience when accessing and viewing it. This means getting your LCP and page speeds as quick as possible will impact user experience and therefore how visitors engage with your content. This will impact how Google ranks your pages as to whether they are useful and easy to view.

Ways you can optimise your webpages for LCP

It’s clear from the above the LCP is going to be an important metric for Google in the future and will therefore be a key part of SEO. So wait, now you have another thing to consider in your SEO strategy? We get it. Search engine optimisation can already feel like a minefield and now you have another thing to think about! But don’t worry, there are some simple things that you and your web developer can do to optimise your webpages. Here are some of the ways that you can optimise your webpages for better LCP:

  • Combat slow servers by optimising your server, caching assets and serving HTML pages cache-first
  • Deal with render-blocking Javascript and CSS by reducing CSS and Javascript blocking times, minifying CSS and deferring non-critical CSS
  • Compress large image and text files
  • Preload the most important resources so they are visible first
  • Use adaptive serving to show different assets based on the network connection of the visitor
  • Combine client-side and server-side rendering for a better user experience and to improve LCP

It’s also worth noting that there are a number of tools available to web developers and website owners to help them get a better understanding of their current LCP and what they can do to improve this. For example, Lighthouse includes support for measuring LCP on your webpages, which can give you an indication of how well (or badly) you’re doing and what needs to be done to improve.

If you want to know more about how this can help, check out this technical guide on how to test your performance using Lighthouse.

In summary

This guide contains a lot of information and there’s certainly a lot to take in. Below is a brief summary of some of the key points you should take away from this guide:

  • Largest Contentful Paint (LCP) is a metric used for measuring how long it takes for the largest content element in the viewport to become visible to the user
  • Using this new metric, web developers are able to understand how quickly a visitor sees the most relevant content on the webpage and they can therefore adjust and optimise websites accordingly
  • There are a number of reasons why LCP will impact the SEO of your website, including that it is a metric designed by Google, that slow loading ages affect crawling and that content is absolutely key to visitors
  • One of the most important ways this metric will impact SEO is that user experience will become even more important for Google’s ranking algorithm. LCP and page speeds impact user experience and therefore how well your webpages will rank moving forward
  • The good news is, there are several ways you can optimise your webpages for better LCP. These include compressing large image and text files, preloading the most important resources and dealing with render-blocking Javascript and CSS. Or you can always hire an SEO agency like us to do it for you!