Website Speed Test

Core Web Vitals, PageSpeed and what actually moves rankings

Performance is a confirmed Google ranking signal — but only at the threshold level. Going from 60 to 90 helps. Going from 90 to 99 rarely moves the needle. The interesting work happens at the bad-to-good transition.

The three Core Web Vitals — Google's official thresholds

Since March 2024 INP replaced FID as the interactivity vital. This tool still reports TBT (Total Blocking Time) as a lab proxy — useful, but field INP data from Google's CrUX dataset is authoritative.

Mobile vs. desktop — which one matters more

Google uses mobile-first indexing since 2021. Mobile scores rank pages, desktop scores are a UX courtesy. If your mobile score is 40 and desktop is 95, treat the desktop number as decoration and fix mobile.

The GEO angle — performance and AI citations

Generative engines (Perplexity, ChatGPT Search) have tight render budgets when fetching candidate sources. A slow page may be skipped entirely from the citation pool, even if the content is perfect. The 4-second mark seems to be the soft cutoff in 2026 — pages slower than that drop out of cited sources noticeably.

The fastest wins per metric

• LCP > 2.5 s → compress hero image (WebP/AVIF), preload it, host on a CDN.
• CLS > 0.1 → explicit width/height on every image and ad slot, no late-loading webfonts.
• TBT / INP high → defer non-critical JS, drop third-party tracking pixels, lazy-load below-the-fold widgets.