See how fast your site really is for the people using it.
Paste one script tag. VitalSigns collects Core Web Vitals from real visitors, shows you the slowest pages, and tells you when a deploy makes things worse.
Add to every page, before </head>
<script defer src="https://vital-signs-nu.vercel.app/v1.js"
data-site="vs_your_site_key"></script>The tag loads a 250-byte loader. The collector is fetched asynchronously at low priority, sends a single beacon when the visitor leaves the page, and never blocks rendering.
Features
Real visitors, not lab runs
LCP, INP and CLS measured in your visitors’ browsers with Google’s web-vitals library, reported at p75 like Search Console does.
Find the slow pages
Every page ranked by how it actually performs, split by device and country, with the element or interaction behind the bad scores.
Know when a deploy hurts
Regression checks compare today with yesterday and alert you by email or Slack: “LCP got 40% worse since release v2.3.”
Fixes, not just numbers
Each slow page gets concrete suggestions based on what was measured: preload this hero image, reserve space for that banner.
How it works
- 1
Add your site
Sign up and enter your domain. You get a site key straight away.
- 2
Paste one script tag
Put it in the <head> of your layout. It is 250 bytes and never blocks rendering.
- 3
Watch real data arrive
Scores show up as visitors leave each page: by page, device and country.