Loading tool…
What does TTFB tell you?
Time-to-first-byte captures server think time, TLS, and network path before the body streams. High TTFB often points to origin slowness, cold starts, or missing caching—pair with full RUM tools for complete pictures.
How to use this tool
Enter a public HTTPS URL. Run the test. Compare runs after config changes. Respect robots and rate limits.
Use cases
CDN validation, regression checks after deploys, comparing API gateways, teaching HTTP timing waterfalls.
Privacy and security
This tool contacts remote URLs or endpoints you provide. Do not probe private networks or third-party sites without permission.