Response Time Checker / Glossary
TLS handshake
The time to agree on encryption after the TCP connection is open. TLS 1.3 needs one round trip, TLS 1.2 needs two; a large certificate chain adds bytes to the first flight.
How we measure it
From the TCP connection to the end of the TLS handshake, per sample (a fresh handshake each time, no resumption).
What good looks like
One round trip plus a few milliseconds of computation; we flag handshakes over 150 ms (median).
How to improve it
- Enable TLS 1.3.
- Use an ECDSA certificate (smaller, faster) and a short chain.
- Staple OCSP where the authority still offers it.
- Enable session resumption for returning visitors.
Measure your site
Three cold samples, every phase, and a diagnosis of what is slow.
Open the Response Time Checker