HTTP2 causes more requests/longer load time?

I am starting to look into HTTP/2, running tests on Windows 10/IIS 10. From what I understand HTTP/2 is enabled there by default for secure connections. Yet when I am browsing a local site from Chrome 67.0.3396.99 - HTTP/2 seems slower, issuing more requests.

HTTP connection: HTTP connection

HTTPS connection: HTTPS connection

Any idea why this is happening?

1 answer

  • answered 2018-07-10 15:42 Barry Pollard

    Your screenshot shows 8 additional requests being loaded over HTTPS so you are not comparing like for like. Investigate what those are and you'll likely have your answer.

    Additionally while the latest version of IIS uses HTTP/2 by default you are better adding the protocol column to the network tab to confirm if this is being used. That way you know whether you are comparing HTTP to HTTPS or HTTP to HTTP/2 (over HTTPS).

    HTTP/2 is primarily faster over high latency connections so you may not notice much difference over low latency connections (e.g. if testing with localhost) but it shouldn't really be any slower because of this (except for perhaps a small additional initial connection SSL/TLS negotiation time for HTTPS).