Response Time Checker / Glossary
TCP connect
The time for the TCP handshake with the server: one round trip. It is mostly the network distance between the visitor and the server that answers.
How we measure it
From the start of the connection to the socket being connected, per sample.
What good looks like
Under 20 ms when the server (or a CDN edge) is near the visitor; transatlantic connections take 70 to 100 ms.
How to improve it
- Serve from a CDN with an edge near your visitors.
- Keep connections alive and reuse them (HTTP keep-alive, HTTP/2).
Measure your site
Three cold samples, every phase, and a diagnosis of what is slow.
Open the Response Time Checker