Core Web Vitals Quick Check

What Core Web Vitals are

Core Web Vitals are Google's three official measures of real-world page experience: Largest Contentful Paint (how fast the main content loads), Cumulative Layout Shift (how much the page jumps around while loading), and responsiveness to input. They're built from real Chrome user data, and Google has confirmed page experience is a ranking factor -- alongside being, simply, what keeps a visitor from bouncing.

Lab data vs. field data

This tool runs a live Lighthouse audit against your page ("lab data") every time you check it, which is the fastest way to catch a regression. When Google has enough real visitor traffic to a page, it also reports genuine field data from the Chrome UX Report -- this tool shows that alongside the lab estimate whenever it's available.

What this tool checks

Paste a URL and this tool asks Google's PageSpeed Insights API to run a mobile Lighthouse audit against it, then reports the overall performance score plus each Core Web Vital individually -- Largest Contentful Paint, Cumulative Layout Shift, Total Blocking Time as a proxy for responsiveness, and First Contentful Paint -- each marked as a pass, a warning, or a fail using Google's own thresholds.

Speed and small businesses

A slow site quietly costs conversions and rankings, and small business sites are often the least optimized simply because nobody's had time to check. Once the basics are fixed, PressCircle helps with the other side of growth -- genuine, verified collaborations with publications in your exact niche.

Frequently asked questions

What are Core Web Vitals?

Google's three official page-experience measures: Largest Contentful Paint (loading speed), Cumulative Layout Shift (visual stability), and responsiveness to input -- all built from real Chrome user data.

Why don't I see 'real visitor data' for my page?

Google only reports field data (from the Chrome UX Report) when a page has enough traffic over the trailing 28 days. Smaller or newer pages often only get the lab estimate, which this tool always shows regardless.

Is this tool free, and how often can I check a page?

It's free with no signup, though checks are limited more strictly than our other tools since each one calls Google's metered PageSpeed Insights API.