why is "Google Hosted Libraries" using gzip compression level 5?

[Hans Henrik Bergan]

these libraries only needs to be compressed once, after that they can be served pre-compressed thousands, or even millions of times, right? 

so i would imagine they'd use gzip -9 to minimize bandwidth usage, and make the library load as fast as possible, but testing on
https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js 

it seems that file is served with gzip compression level 5... why? that would make sense if they're compressing the file on-the-fly for every request and they're trying to minimize cpu-utilization, but storing it pre-compressed would use way less cpu anyway, so that probably isn't it.. why is it served using gzip -5?

[Philipp Wollermann]

Hi,

good question. I'll try to find out and will get back to you here, but I won't have time for it before next Monday. I've put this on snooze so I don't forget - but if I do, please feel free to ping me again here!

Cheers,

Philipp