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Technical 2 Feb 2026 5 min read

Core Web Vitals Reporting: What to Show Clients

Core Web Vitals are a Google ranking factor, but most clients have never heard of LCP, CLS, or INP. Here's how to report on them clearly, explain why they matter, and show the impact of improvements.

What Are Core Web Vitals?

Core Web Vitals are three metrics Google uses to measure real user experience on your website. They became a confirmed ranking factor in 2021 and remain part of Google's page experience signals. For SEO agencies, they matter because poor scores can hold back rankings, and improvements can provide a measurable boost.

The three metrics measure loading speed, visual stability, and interactivity. Google collects this data from real Chrome users visiting your site (called "field data"), so the scores reflect actual experience, not lab conditions.

LCP — Largest Contentful Paint

What it measures

How long it takes for the biggest visible element on the page to load. This is usually a hero image, a large text block, or a video thumbnail. It's the metric that most closely represents "how fast does the page feel?" from the user's perspective.

Thresholds

Good

≤ 2.5s

Needs Work

≤ 4.0s

Poor

> 4.0s

How to explain it to clients

"LCP measures how quickly the main content on your page loads. Think of it as the moment a visitor can actually see what your page is about. Your homepage currently loads its main content in 1.8 seconds, which is in the 'good' range. Your product category pages are at 3.2 seconds, which needs improvement — we're optimising the hero images to fix this."

Common fixes

Optimise and compress hero images (WebP format, proper sizing)
Preload the LCP element so the browser fetches it immediately
Remove render-blocking JavaScript and CSS above the fold
Use a CDN to reduce server response time
Implement lazy loading for images below the fold (but NOT the LCP image)

CLS — Cumulative Layout Shift

What it measures

How much the page layout shifts unexpectedly while loading. You know when you're about to click a button and the page jumps because an image or ad loaded above it? That's layout shift. CLS measures the total amount of unexpected shifting that happens during the page's lifetime.

Thresholds

Good

≤ 0.1

Needs Work

≤ 0.25

Poor

> 0.25

How to explain it to clients

"CLS measures how stable your page is while loading. A low score means nothing jumps around. Your site scores 0.05 — that's excellent. Visitors can read and click without the page shifting underneath them. Some of your blog pages score 0.18 because of ads loading late — we're adding size placeholders to fix that."

Common fixes

Always set width and height attributes on images and videos
Reserve space for ads and embeds with CSS aspect-ratio or min-height
Avoid inserting content above existing content after page load
Use font-display: swap for web fonts to prevent flash of invisible text
Load third-party scripts asynchronously so they don't block layout

INP — Interaction to Next Paint

What it measures

How responsive the page is when users interact with it. INP replaced First Input Delay (FID) in March 2024 as a Core Web Vital. While FID only measured the first interaction, INP measures all interactions throughout the page visit and reports the worst one. It captures the time from when a user clicks, taps, or presses a key to when the browser updates the display.

Thresholds

Good

≤ 200ms

Needs Work

≤ 500ms

Poor

> 500ms

How to explain it to clients

"INP measures how quickly your site responds when someone clicks a button or interacts with the page. A score under 200ms means the site feels instant. Your site scores 150ms overall, which is good. Two pages with heavy JavaScript score 380ms — they feel sluggish when users try to interact. We're optimising the scripts on those pages."

Common fixes

Break up long JavaScript tasks into smaller chunks (yield to the main thread)
Defer non-critical JavaScript so it doesn't block interactions
Reduce the amount of JavaScript on the page overall
Use web workers for heavy computations that don't need DOM access
Audit third-party scripts — chat widgets and analytics tags are common offenders

How to Present Core Web Vitals in Client Reports

The key is simplicity. Most clients don't need to understand the technical details — they need to know: are we passing, and is it getting better?

Traffic light summary: Show LCP, CLS, and INP as green/amber/red indicators. This gives an instant health check that any client can understand.
Trend over time: Show the score for each metric over the past 3–6 months. Clients want to see improvement, not just a snapshot.
Page-level breakdown: If specific pages have poor scores, call them out with the current score and your plan to fix them.
Before and after: When you fix a CWV issue, show the before and after scores. This is the most powerful way to demonstrate technical SEO value.
Business impact: Connect CWV improvements to outcomes: "After improving LCP from 4.1s to 2.3s on your product pages, we saw a 15% increase in conversions on those pages."

Where to Get CWV Data

For client reports, always use field data (real user data) rather than lab data (synthetic tests):

Google Search Console: Core Web Vitals report shows pass/fail status for all URLs, grouped by status. Best for reporting.
PageSpeed Insights: Shows both field data (from CrUX) and lab data for individual URLs. Good for diagnosing specific pages.
CrUX Dashboard: Google's Chrome User Experience Report, available as a Looker Studio template. Shows historical trends.
web-vitals JavaScript library: Add to the client's site to collect CWV data directly into GA4 as custom events.

For the complete picture of GSC data beyond CWV, read our guide on Google Search Console reporting. And for understanding all the metrics that belong in a client report, see what to include in an SEO report.

Key takeaway: Core Web Vitals reporting should be simple: traffic lights for status, trends for progress, and before/after comparisons for improvements. Don't bury clients in technical jargon. Translate every metric into user experience and business impact.

Include Core Web Vitals in every report

ReportBolt pulls CWV data automatically. Traffic light indicators, trends, and page-level breakdowns.