Largest Contentful Paint (LCP)
Measures when the largest visible content element is rendered during this lab page load.
Free website speed test
Test your website speed in a real browser.
Run a free page speed test and see page-load metrics, server response time, page weight, JavaScript impact and the resources most likely to be slowing the page down.
Free · No signup required · Real Chromium lab test
What this tool measures
A broader website performance test, not just one score
Time to First Byte (TTFB)
Measures how long the browser waits before the first response byte arrives.
Total Blocking Time (TBT)
Shows how much long-task main-thread work blocks the page during the lab load.
Cumulative Layout Shift (CLS)
Measures unexpected visual movement observed during the controlled browser run.
Page weight & resources
Tracks transferred bytes and resource count so heavy pages and asset growth are visible.
JavaScript CPU & blockers
Attributes sampled browser CPU and classifies render-blocking, LCP-critical and bandwidth-heavy resources.
Interpret the result
Use the report to find the biggest delay, then retest.
A useful website speed test should explain the load, not only grade it. Start with LCP, TTFB and TBT, then inspect the resource and JavaScript sections to see what is contributing to the delay.
The result is a controlled lab measurement from one browser run. It is designed for repeatable debugging and comparison, while real-user field data can differ because visitors use different devices, networks and locations.
Methodology
SiteState loads the URL in a controlled desktop Chromium profile and reports synthetic lab metrics from that run. It does not claim that a one-off lab result is the same as real-user field performance.
FAQ
Common questions about this speed test
Is this website speed test free?
Yes. You can run the SiteState website speed test without creating an account. Continuous monitoring requires an account because SiteState then stores monitor configuration and performance history.
Is a website speed test the same as PageSpeed Insights?
No. SiteState runs its own controlled Chromium lab check and focuses on page state, resource blockers, JavaScript impact and monitoring continuity. PageSpeed Insights has its own Lighthouse and CrUX methodology.
What metrics does the page speed test measure?
The SiteState browser test can report LCP, CLS, TBT, FCP, load timing, TTFB, transferred bytes, resource counts, sampled JavaScript CPU and blocker analysis.
Can I monitor website speed over time?
Yes. After the free test you can add the same site to SiteState and keep browser performance under continuous synthetic monitoring with regression detection.
Related free tools
Test another part of website speed
Core Web Vitals Test
Check synthetic LCP and CLS with a clear lab methodology.
Open toolTTFB Test & Checker
Measure Time to First Byte and connection timing.
Open toolLCP Checker
Focus on Largest Contentful Paint and LCP-critical resources.
Open toolWebsite Page Analyzer
Analyze page weight, resources and JavaScript cost.
Open toolContinuous performance
Need more than one test? Website performance monitoring keeps compatible browser metrics and regression history over time. Performance.
A one-off speed test is only a snapshot.
SiteState can keep the same website under continuous monitoring and detect when performance changes.