Free tool

Is your site cloaking PageSpeed?

Some agencies and freelancers “fix” a slow site by showing Google's tools a stripped-down, fast page while real visitors still get the bloated one. It buys a pretty 95+ score and changes nothing for users. This checker compares what Google's PageSpeed Insights actually saw against the page a normal visitor receives — and flags structural mismatches, with the evidence.

A single public page (the one that was “optimized”). We check it as Google does — mobile.

How the test works (and what it can't prove)

Naïvely fetching a page twice with different user-agents only catches the crudest cloaking, because sophisticated setups key on the visitor's IP address, not the user-agent string — and they only serve the stripped page to Google's IPs. So this tool uses two complementary probes:

  1. Google's own view

    We call the PageSpeed Insights API, so Google's infrastructure fetches the page (real Google IPs, real Lighthouse). Its lab score, screenshot and resource counts are the ground truth for what Google was shown.

  2. Lab vs. real users

    PSI also reports field data from real Chrome users (CrUX). A high lab score paired with a slow real-user experience is the classic fingerprint of IP-based cloaking — the score nobody actually feels.

  3. The user-agent flip

    From our server we request the raw HTML three times — twice as a normal mobile visitor, so we learn which third-party hosts rotate naturally between identical loads, then once with a Lighthouse user-agent. If the markup changes when only the user-agent changes — beyond that natural churn — that isolates user-agent-based cloaking.

Why we never just accuse

Honest sites differ between loads all the time — A/B tests, personalization, geo-targeting, randomized ads, lazy-loading. And Google explicitly permits hiding the cookie-consent banner from Lighthouse, so a missing banner is a false positive, not a smoking gun. This tool only flags structural mismatches (whole sections, many missing scripts, a great lab score that real users never feel), requires independent signals to corroborate before it escalates — a size-only or host-only difference is marked as worth a look, never as an accusation — and shows you the evidence so you can judge. A “possible cloaking” result is a reason to investigate, not proof.

Want a definitive answer for a specific page? A PageSpeedAudit report carries this exact test — same thresholds, same honesty ladder — as its integrity gate, so no verdict is ever built on a measurement of the wrong page. It then reads your real markup and headers, separates genuine optimization from score theater, and gives you the actual fixes — the honest version of a fast site.

Curious how common this actually is? We ran this exact user-agent probe across the top 2,000 sites and published the results — read How many sites cheat PageSpeed?, our cloaking prevalence census.