Overview
See live Core Web Vitals on any page: LCP, CLS & INP with ratings, the LCP element and layout-shift diagnostics. Free.
Core Web Vitals Checker shows you how any page really performs — live, in a clean overlay you can drag anywhere. Built for developers and SEOs who want LCP, CLS, and INP at a glance without opening DevTools. Click the icon and a heads-up overlay appears with your Core Web Vitals, each rated Good, Needs work, or Poor using Google's thresholds. No sign-up, no ads, no tracking. ━━━━━━━━━━━━━━━━━━━━ WHAT YOU CAN DO ━━━━━━━━━━━━━━━━━━━━ ⚡ LIVE LCP, CLS & INP The three Core Web Vitals, updating as you scroll and interact with the page. 🟢 CLEAR RATINGS Color-coded Good / Needs work / Poor for every metric, using Google's official thresholds. 🔍 ACTIONABLE DIAGNOSTICS See the element responsible for LCP (click to highlight it on the page), the biggest layout shift and what caused it, plus TTFB and FCP for context. 🧲 DRAGGABLE OVERLAY Pin it anywhere on the page. Press Esc to close. Great for demos, audits, and screenshots. ━━━━━━━━━━━━━━━━━━━━ PRIVATE BY DESIGN ━━━━━━━━━━━━━━━━━━━━ - 100% free, forever - No account or sign-in - No ads, no analytics, no tracking - No network calls — everything runs on your device - Runs only on the tab you click, and only when you click it - Just two permissions (activeTab + scripting), and no remote code How it works: real Core Web Vitals accumulate during page load, so the overlay reads the browser's buffered performance data when you open it — capturing this page load without an always-on background script. INP grows as you interact. ━━━━━━━━━━━━━━━━━━━━ WHO IT'S FOR ━━━━━━━━━━━━━━━━━━━━ Front-end developers, performance engineers, and technical SEOs. Made by the team at seolust.com.
Details
- Version1.0.0
- UpdatedJuly 27, 2026
- Size25.59KiB
- LanguagesEnglish (United States)
- DeveloperWebsite
Email
info@clock7.com - Non-traderThis developer has not identified itself as a trader. For consumers in the European Union, please note that consumer rights do not apply to contracts between you and this developer.
Privacy
This developer declares that your data is
- Not being sold to third parties, outside of the approved use cases
- Not being used or transferred for purposes that are unrelated to the item's core functionality
- Not being used or transferred to determine creditworthiness or for lending purposes
Support
For help with questions, suggestions, or problems, visit the developer's support site
