HAR timing glossary

What each phase of the request waterfall means, and what a large value in it usually points at.

• Blocked — Time spent queued before the browser could even open a connection for this request.
• DNS — Time spent resolving the hostname to an IP address.
• Connect — Time spent establishing the TCP connection, including the TLS handshake for HTTPS.
• SSL / TLS handshake — The portion of connect time spent negotiating TLS, shown separately for inspection.
• Send — Time spent writing the request onto the wire.
• Wait (TTFB) — Time between the request finishing transmission and the first byte of the response arriving.
• Receive — Time spent reading the response body after the first byte arrived.