I think you're right that TLS doesn't explain the difference shown above, but for completeness: TLS 1.3 can reduce the round trips from 3 to 2 on session resump

I think you're right that TLS doesn't explain the difference shown above, but for completeness: TLS 1.3 can reduce the round trips from 3 to 2 on session resumption. [1] Depending on your Internet connection, that could be a lot more than milliseconds. I don't think `curl` uses it by default though. [1] https://blog.cloudflare.com/introducing-0-rtt/ https://blog.cloudflare.com/introducing-0-rtt/