I was refering to a sane default of 6 TCP sockets that some browsers use per host when using HTTP/1.1. I don't think this is standardized, so its just an implem

I was refering to a sane default of 6 TCP sockets that some browsers use per host when using HTTP/1.1. I don't think this is standardized, so its just an implementation detail and might vary across browsers and plattforms. Maybe you can even increase this in your browser settings. From a quick glance at the HTTP/2 spec, it seems the actual number of multiplexed steams is configurable per session: https://httpwg.org/specs/rfc7540.html#SettingValues https://httpwg.org/specs/rfc7540.html#SettingValues (SETTINGS_MAX_CONCURRENT_STREAMS). Of course, OSes have limits how much outgoing TCP connections you can have (per user, per process, system wide) but I think will be much higher than 1000. Edit: Firefox by default uses no more than 900 parallel HTTP connections (check your about:config page), and I assume this holds true for all windows/tabs combined - which is plenty.