# Core Web Vitals Fixes: LCP, INP and CLS

Source: https://dijitulsupport.co.uk/core-web-vitals-fixes/
Updated: 2026-10-10

> dijitul support fixes failing Core Web Vitals for UK websites. We diagnose which metric is failing, Largest Contentful Paint, Interaction to Next Paint or Cumulative Layout Shift, trace it to the cause on your pages and fix it, then validate in Search Console. One-off fixes are £45 an hour + VAT.

## Common symptoms

- Search Console shows "LCP issue: longer than 2.5s (mobile)"
- An "INP issue: longer than 200ms" warning has appeared
- "CLS issue: more than 0.1" is flagged on lots of URLs
- Buttons feel laggy when tapped on a phone
- Text or buttons jump as adverts, banners or fonts load
- PageSpeed Insights passes in the lab but fails on real-user data

## Key facts

- Core Web Vitals are three metrics: LCP (loading), INP (responsiveness) and CLS (visual stability)
- Google's "good" thresholds: LCP 2.5 seconds or less, INP 200 milliseconds or less, CLS 0.1 or less
- Google judges each metric at the 75th percentile of real visits, split by mobile and desktop
- INP replaced First Input Delay (FID) as a Core Web Vital in March 2024
- Search Console field data is a rolling 28-day window, so fixes take weeks to show
- We fix and click "Validate fix" in Search Console for you
- Ad-hoc work £45 an hour + VAT, or ongoing care from £25 a month + VAT

## What the three metrics mean

**Largest Contentful Paint (LCP)** measures how long the biggest thing in view, usually a hero image or headline, takes to appear. Google wants it within 2.5 seconds.

**Interaction to Next Paint (INP)** measures how quickly the page visibly responds when someone taps, clicks or types. It replaced First Input Delay in March 2024 and is stricter, because it looks at interactions throughout the visit, not just the first one. Good is 200 milliseconds or less.

**Cumulative Layout Shift (CLS)** measures how much the page jumps about while loading. Good is 0.1 or less. A cookie banner that pushes the page down, or an image without width and height set, are classic causes.

Google assesses each at the 75th percentile of real visits, so three quarters of your visitors need a good experience for the URL to pass.

## Fixing slow LCP

LCP problems break down into four parts: server response time, the delay before the browser discovers the main image, the time to download it, and render delay. Typical fixes we apply:

- Cut Time to First Byte with proper page caching and a current PHP version
- Stop lazy-loading the hero image (a common mistake, since lazy-loading delays the very element LCP is timing)
- Add *fetchpriority="high"* and a preload hint to the LCP image
- Serve the hero in WebP or AVIF at the size it is actually displayed
- Remove render-blocking CSS and JavaScript from the head, and inline critical CSS where it helps
- Self-host web fonts and use *font-display: swap*

## Fixing poor INP

INP is the metric we see failing most on WordPress sites built with heavy page builders, and on shops with lots of tracking tags. The browser's main thread is busy running JavaScript, so it cannot respond to a tap. We use Chrome's performance panel to find long tasks, then:

- Remove or delay non-essential third-party scripts (chat widgets, heatmaps, duplicate analytics tags)
- Load scripts only on the pages that need them
- Defer JavaScript that is not needed for the first interaction
- Simplify mega-menus, sliders and filters that do heavy work on every click
- Reduce very large DOM sizes, which make every update slower

## Fixing layout shift (CLS)

Layout shift is usually the quickest of the three to fix. We set explicit width and height (or aspect-ratio) on images, video and iframes, reserve space for adverts and embeds, make cookie banners overlay the page rather than push it down, and stop fonts swapping in at a very different size by matching fallback font metrics. Content injected above existing content after load, such as a promo bar, is moved or given reserved space.

## Where the problems usually come from

Most failing sites we see are not badly built, they have just accumulated weight. A theme bought years ago, a page builder, an events plugin, a booking widget, a cookie banner, a live chat tool, Google Tag Manager running five tags and a Facebook pixel. Each was added for a good reason. Our job is to find which ones actually cost you, keep what earns its place, and load the rest only where it is needed or after the page has become usable. We also check that mobile, not desktop, is passing, since that is where most sites fail and where most visitors are.

## Validation and what it costs

Search Console's Core Web Vitals report uses a rolling 28 days of real Chrome user data, so after we deploy a fix we start validation and it can take up to four weeks to clear. We will tell you which fixes we expect to move which metric, so you are not left guessing.

Core Web Vitals work is billed at **£45 an hour + VAT**, 30-minute minimum then 15-minute blocks. If your site is generally slow rather than failing one metric, start with website speed optimisation. To stop scores slipping as the site changes, a Business plan at £50 a month + VAT includes an hour of fixes every month. Send us your URL and the Search Console report.

## FAQs

### What are good Core Web Vitals scores?

Google's thresholds for "good" are Largest Contentful Paint of 2.5 seconds or less, Interaction to Next Paint of 200 milliseconds or less and Cumulative Layout Shift of 0.1 or less, each measured at the 75th percentile of real visits on mobile and desktop separately.

### Why do I pass in PageSpeed Insights but fail in Search Console?

The lab test simulates one visit on one device. Search Console uses real visits from Chrome users over 28 days, including slow phones and poor connections. INP in particular cannot be measured properly by a lab test, because it depends on real people tapping and typing.

### How long until Search Console shows the fix?

Up to 28 days. The report is based on a rolling 28-day window of real-user data, so the old slow visits have to age out. dijitul support starts validation in Search Console straight after deploying a fix so you can track progress.

### Do Core Web Vitals affect Google rankings?

They are part of Google's page experience signals, but relevance and content quality matter far more. The bigger reason to fix them is visitors: slow, jumpy, laggy pages lose enquiries and sales. We treat ranking benefits as a bonus, not a promise.

### What replaced First Input Delay?

Interaction to Next Paint (INP) replaced First Input Delay as a Core Web Vital in March 2024. INP is harder to pass because it measures responsiveness across all interactions in a visit, not just the delay before the first one is handled.

### How much do Core Web Vitals fixes cost?

dijitul support charges £45 an hour + VAT, with a 30-minute minimum and then 15-minute blocks. CLS fixes are often quick; INP on a script-heavy site takes longer. We look first and give you a time estimate before starting.

## Pricing and contact

Support plans from £25 a month + VAT, or £45 an hour + VAT for one-off fixes. Plans: Essential £25/month + VAT (Website software updates (core, plugins, themes) applied and checked, Daily backups, Uptime monitoring, Security monitoring); Business £50/month + VAT (Everything in Essential, 1 hour of fixes or changes every month, Priority support); Complete £99/month + VAT (Everything in Business, 3 hours of fixes or changes every month, IT and Microsoft 365 helpdesk for your team). Ad-hoc support is £45 an hour + VAT. The first 30 minutes are the minimum charge, then we bill in 15-minute blocks. Contact: 01623 650333, support@dijitul.uk, https://dijitulsupport.co.uk/contact/