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Core Web Vitals

Core Web Vitals

Core Web Vitals (CWV for short) are four numbers that describe how your website feels to real visitors. Slow or janky sites hurt engagement, SEO rankings, and conversion. Voris can collect these numbers directly from your visitors’ browsers and show you how your site is performing.

This feature is off by default. Turn it on in site settings when you are ready — see Turning it on below.

What each metric means

You will see four metrics in the Core Web Vitals panel on your dashboard. Each is colour-coded green (Good), yellow (Needs improvement), or red (Poor) based on Google’s published thresholds.

LCP — Largest Contentful Paint

How long it takes for the largest visible thing on your page (usually a hero image or headline) to appear. Measured in seconds.

  • Good: 2.5 seconds or less.
  • Needs improvement: 2.5 to 4 seconds.
  • Poor: more than 4 seconds.

If your LCP is red, common causes are oversized hero images, slow servers, and render-blocking scripts.

INP — Interaction to Next Paint

How quickly your page responds the first time a visitor clicks, taps, or types. Measured in milliseconds.

  • Good: 200 ms or less.
  • Needs improvement: 200 to 500 ms.
  • Poor: more than 500 ms.

If INP is red, it usually means heavy JavaScript is tying up the page. Fewer tags and lighter frameworks help.

CLS — Cumulative Layout Shift

How much the page visibly jumps around as it loads. Measured as a unitless score.

  • Good: 0.1 or less.
  • Needs improvement: 0.1 to 0.25.
  • Poor: more than 0.25.

If CLS is red, common causes are images without explicit width and height, ads that push content down, and fonts that swap late.

TTFB — Time to First Byte

How long after a visitor requests your page before the first byte comes back. Measured in milliseconds.

  • Good: 800 ms or less.
  • Needs improvement: 800 to 1800 ms.
  • Poor: more than 1800 ms.

If TTFB is red, the bottleneck is usually your hosting provider, a slow backend, or a server that is physically far from most of your visitors.

FCP — First Contentful Paint

How long after a visitor requests your page before the first piece of content (text or image) appears. Measured in milliseconds.

  • Good: 1800 ms or less.
  • Needs improvement: 1800 to 3000 ms.
  • Poor: more than 3000 ms.

FCP is a supporting metric, not one of the three Core Web Vitals, but it is shown alongside them because it is an early signal of the same loading problems that hurt LCP.

Turning it on

CWV collection is off by default so your site does not send extra data without you choosing to.

  1. From your site’s dashboard, click the gear icon to go to Site settings.
  2. Find the Core Web Vitals collection toggle.
  3. Switch it on.
  4. Save changes.

From that point forward, your tracking script will collect CWV data from real visitors. You should see numbers appear in the dashboard panel within a few hours of real traffic.

Core Web Vitals toggleCore Web Vitals toggle

What if the panel says “No CWV data yet”?

You will see this in two situations:

  • You have not enabled CWV collection yet. Flip the toggle in site settings.
  • You enabled it very recently and no visitors have loaded the site yet. Give it some time and check back.

Are Core Web Vitals collected in Mode A?

Yes. CWV data is aggregated across visitors just like pageviews, so it does not require cookies or visitor IDs. You can turn it on in Mode A without changing anything else about your privacy posture.

How often do the numbers update?

The dashboard panel reflects the currently selected time period, just like everything else on your dashboard. Change the period selector at the top of the page to see CWV over Today, Yesterday, 7 days, or 30 days.

Understanding your dashboardSite settings