Free website tools
Diagnose website performance and health with focused tools.
SiteState groups its free tools into two clear clusters: browser performance and website health. Every tool is connected to the same underlying product, so one-off diagnosis can turn into continuous monitoring without starting over.
9 tool
Performance tools
Browser-based tools for page speed, Core Web Vitals, rendering, JavaScript, page weight and performance diagnostics.
View all performance tools8 tool
Website health tools
Live website diagnostics for uptime, SSL, DNS, HTTP responses, redirects, headers and response timing.
View all website health toolsAll tools
17 live website diagnostics
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.
core web vitals test
Core Web Vitals Test
Check synthetic LCP and CLS with TBT diagnostics and an explicit lab methodology.
ttfb test · ttfb checker · time to first byte test
TTFB Test & Checker
Measure first-byte delay with DNS, TLS, redirect and browser-load context.
lcp test · largest contentful paint checker
LCP Test
Measure Largest Contentful Paint and inspect LCP-critical and render-blocking resources.
cls test · cumulative layout shift test
CLS Test
Measure Cumulative Layout Shift during a controlled Chromium page load.
total blocking time test · tbt test
Total Blocking Time Test
Measure TBT together with JavaScript CPU, third-party impact and main-thread blocking.
website 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.
render blocking resources test · css js checker
Render Blocking Resources Test
Find resources classified as render-blocking, LCP-critical, bandwidth-heavy or third-party.
website page analyzer · page weight test · website size analyzer
Website Page Analyzer
Measure transferred bytes, resource count, heavy assets and page-load context.
website uptime checker · is my website down
Website Uptime Checker
Check whether a public website is responding right now and inspect HTTP status and timing.
ssl checker · ssl certificate test
SSL Checker
Check HTTPS, browser-visible certificate validity, TLS protocol, issuer and expiry details.
security headers checker · hsts csp
Security Headers Checker
Check six common browser-facing security headers and see which baseline headers are missing.
check website redirects · check site redirects · redirect checker
Redirect Checker
See redirect count, final destination URL, final status and browser timing context.
dns checker · dns lookup
DNS Checker
Look up A, AAAA, CNAME, MX, NS and TXT records for the public website hostname.
http status code checker · url status
HTTP Status Code Checker
Check the final HTTP status, final URL, redirect count and response timing.
http headers checker · response headers
HTTP Headers Checker
Inspect sanitized public response headers from the final main document.
website response time test · server timing
Website Response Time Test
Break response time into DNS lookup, connection, TLS, TTFB and page-load timing.