SiteState tool cluster
Performance tools
Use focused browser tests for page speed, Core Web Vitals, rendering, JavaScript and page weight. Every tool runs on the same SiteState synthetic engine, so a one-off diagnosis can move naturally into continuous performance monitoring.
website speed test · page speed test
Website Speed Test
Measure LCP, CLS, TBT, TTFB, page weight, JavaScript CPU and the resources slowing the page down.
Open free toolcore web vitals test
Core Web Vitals Test
Check synthetic LCP and CLS with TBT diagnostics and an explicit lab methodology.
Open free toolttfb test · ttfb checker · time to first byte test
TTFB Test & Checker
Measure first-byte delay with DNS, TLS, redirect and browser-load context.
Open free toollcp test · largest contentful paint checker
LCP Test
Measure Largest Contentful Paint and inspect LCP-critical and render-blocking resources.
Open free toolcls test · cumulative layout shift test
CLS Test
Measure Cumulative Layout Shift during a controlled Chromium page load.
Open free tooltotal blocking time test · tbt test
Total Blocking Time Test
Measure TBT together with JavaScript CPU, third-party impact and main-thread blocking.
Open free toolwebsite javascript performance · third-party javascript
Website JavaScript Performance Test
Inspect sampled JavaScript CPU, third-party script impact and the scripts using the most main-thread time.
Open free toolrender blocking resources test · css js checker
Render Blocking Resources Test
Find resources classified as render-blocking, LCP-critical, bandwidth-heavy or third-party.
Open free toolwebsite page analyzer · page weight test · website size analyzer
Website Page Analyzer
Measure transferred bytes, resource count, heavy assets and page-load context.
Open free toolFrom one-off check to continuous state
Website performance monitoring
Use the free tools for point-in-time diagnosis. When the website matters continuously, move the same site into SiteState monitoring so changes, incidents and regressions build a useful history.
Explore website performance monitoring