Understanding Core Web Vitals is an important part of analyzing your website performance metrics and understanding how Google measures user experience through real-world signals. When Core Web Vitals were first announced, Google described three key metrics: Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS). Looking ahead to 2026, things have changed.
First Core Web Vitals
To understand what has changed, it helps to recap where things first started. LCP measured how quickly the largest content element (an image or heading) on a page became visible to the user. FID looks at how long a user has to wait for a response to their action. CLS measures the amount of shift in the page layout that occurs when the page is still loading, which could cause users to click on the wrong element if they weren’t careful.
Although a great start, these three metrics do have some limitations. FID in particular, is limited in that it only records the very first interaction, resulting in the system overlooking browse-session-ending performance issues.
Interaction to Next Paint (INP) Replaces FID
One of the biggest developments in Core Web Vitals is the removal of FID and the adoption of Interaction to Next Paint (INP). INP was added as a Core Web Vital in March 2024 and is set to remain a primary focus in 2026.
INP will assess a page’s responsiveness across an entire visit as opposed to just a first click.
It measures the latency between any user interaction – like clicking a button, tapping on a menu, filling out a form – and the subsequent visual update rendered by the browser. An INP score that is 200ms or less is good, and anything above 500ms is bad.
For small business websites, this is significant as the common cause of this are the slow execution of javascript, third party scripts and bloated plugins. If your site uses a lot of plugins, analytics tags and live chat widgets, they will certainly slow down interaction times.
CLS and LCP Are Still Very Much Alive
Google still lists LCP and CLS as official Core Web Vitals and continue to include it as part of Page Experience signals. The thresholds for 2026 have not changed – a good LCP is less than 2.5 seconds, and a good CLS is < 0.1 – however, the reasons sites are failing have changed.
Issues with LCP are now tied to render blocking resources and slow server response times. For websites using video backgrounds, full-width hero images, or sections with lazy loading, those that are hosted on budget shared hosting are the first to suffer performance issues.
For CLS, your website will be more likely to have issues in 2026 if it has web fonts that load late, consent banners that push content down the page, and ads that are dynamically inserted and push content down the page. If your site uses a consent management platform, it may be impacting your layout stability score.\
Smooth Scrolling and the Growing Role of Time to First Byte
In addition to the Core Web Vitals, Google has increasingly added TTFB (Time to First Byte) as one of the metrics that websites should be focused on.
TTFB is an indicator of how fast your server starts communicating with a user’s browser. Although it is not a ranking factor yet, a bad TTFB will make obtaining a good LCP score almost impossible. Best to keep an eye on it.
For small business websites, the best option for improving TTFB is still hosting upgrades, enabling server-side caching, and utilising Content Delivery Networks (CDN).
Checking Core Web Vitals
The Core Web Vitals report in the Google Search Console is the starting point. It’s easy to spot the failed URLs and see the real user data. You can also see lab and field data combined with improvement suggestions in Google PageSpeed Insights.
Tools such as web.dev and the Chrome User Experience Report (CrUX) provide a more in-depth analysis and allow you to examine your site’s performance against websites of your choosing.
Are Core Web Vitals Important for Rankings?
Core Web Vitals are ranking factors, although Google is quite clear that most critical are relevance and authority of the content. The faster a web page loads, the higher it is ranked. In such a situation, where all other factors are equal, the difference in ranking will be substantial especially in the local market.
If you do not know how optimised your site is, you can request a full performance audit from Diggit that will outline the changes most likely to positively impact your business.