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Paste a URL and I'll query Google's own PageSpeed Insights API for mobile and desktop — real Core Web Vitals field data where Google has enough real-user traffic, real lab data otherwise. Every click you pay for lands on this page; a slow LCP or a janky CLS is money leaking out of that click before it converts.
Real Google PSI call, mobile + desktop.
Field (CrUX) + lab, no invented numbers.
LCP, INP, CLS vs Google's own thresholds.
Google's own thresholds
| Metric | Good | Needs improvement | Poor |
|---|---|---|---|
| LCP — Largest Contentful Paint | ≤ 2.5s | ≤ 4.0s | > 4.0s |
| INP — Interaction to Next Paint | ≤ 200ms | ≤ 500ms | > 500ms |
| CLS — Cumulative Layout Shift | ≤ 0.10 | ≤ 0.25 | > 0.25 |
Why this exists
Core Web Vitals aren't an SEO checkbox — they measure whether a real visitor sees your content fast (LCP), whether the page responds when they tap something (INP), and whether things jump around while they're trying to read or click (CLS). Every one of those failures is a moment where a paid or organic visitor gives up before your offer even loads.
This tool doesn't simulate anything of its own — it calls Google's PageSpeed Insights API directly and reports back exactly what Google measured, labeled clearly as field data (real Chrome users) or lab data (a simulated run), scored against Google's own published thresholds. If your site's numbers are green, that's real. If they're red, that's real too.
Waseem, building from Bali · info@skynetjoe.com
Quick answers
Directly from Google's PageSpeed Insights (PSI) v5 API — the same API that powers pagespeed.web.dev. We call it server-side (so an optional API key, if configured, never ships to the browser) and pass through exactly what Google returns: field data (real Chrome users, via the Chrome UX Report) when available, and lab data (a simulated Lighthouse run) as a fallback or supplement. Nothing here is estimated by us.
Field data is aggregated from real Chrome users who actually visited the page over the last 28 days (Chrome UX Report / CrUX) — it reflects real devices and real networks. Lab data is a single simulated run against a fixed device/network profile. Field data is the ground truth Google uses for ranking signals; lab data is a useful proxy when a page hasn't collected enough real-user traffic (common for lower-traffic and new pages).
LCP (Largest Contentful Paint): good ≤2.5s, needs improvement ≤4s, poor beyond that. INP (Interaction to Next Paint): good ≤200ms, needs improvement ≤500ms, poor beyond. CLS (Cumulative Layout Shift): good ≤0.1, needs improvement ≤0.25, poor beyond. These are Google's published Core Web Vitals thresholds, not ours.
Because it's a real call to Google's PSI API for both mobile and desktop, and Google's lab test genuinely runs a Lighthouse pass against your page — that typically takes 10-20 seconds. There's no way to fake that faster without inventing numbers, which we won't do.
PSI's keyless quota is shared and IP-based, so it can occasionally rate-limit under heavy shared usage. If that happens the tool tells you plainly rather than showing a fake score — try again shortly, or use the full PSI report link for a direct check.
Updated August 2026