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Backlnk
Free audit

Page Speed Test (Lab)

Measure loading performance in a real browser: LCP, layout shift, blocking time and what slows the page.

One page, measured on emulated mobile and desktop.

Free, no sign-up. Every audit is saved privately to this browser — find it later in your history.

Your saved reports

What this tool does

Loads the page in Backlnk's isolated Chromium with a mobile profile (4× CPU slowdown, 4G-like network) and a desktop profile, records Largest Contentful Paint, Cumulative Layout Shift, Total Blocking Time, First Contentful Paint and server response time, and breaks down the requests, bytes and render-blocking resources behind them.

What you get

  • LCP, CLS, TBT, FCP and TTFB for mobile and desktop
  • The LCP element and the largest resources
  • Request and byte breakdown by type, render-blocking resources

Scope

One page, two lab runs (mobile and desktop).

Pages are fetched politely by BacklnkBot, robots.txt is respected, and only public websites can be audited. Every finding shows the evidence it is based on and when it was measured.

Limitations

  • • These are lab measurements from one location through Backlnk's network; real visitors' experience (field data) can differ.
  • • Field data from Google's Chrome UX Report is not included.
  • • Results vary between runs; compare trends, not single milliseconds.

Frequently asked questions

Why is this different from PageSpeed Insights?
Different machines, locations and network conditions produce different lab numbers, and PageSpeed Insights also shows field data from real Chrome users. Use this report for causes and trends.

Guides

Learn the topic behind the page speed check

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