Midori
Procedure: Set home page to blank, disable scripts, restart.
Result:
On startup: Zero (0) packets sent.
On opening of preferences only this was shown in tcpdump:
IP pc.49352 > 239.255.255.250.ssdp: UDP, length 132
IP pc.49352 > 239.255.255.250.ssdp: UDP, length 133
but only the first time the browser is started. Shutting down the browser and
opening preferences again doesn't show such packets in tcpdump (unless the
machine is rebooted).
Browsing to https://fsf.org/txt shows only communication with fsf.org and no
packet sending to any other hosts whatsoever.
Additional info: Acid3 test shows 100/100 (with enabled JS). It also has
quite a few built in extensions, one of them an adblocker which unfortunately
is not as advanced as my favorite uMatrix and uBO. Another disadvantage I
notice: it has some issues with color management making images appear
oversaturated.
A bug noticed: opening https://browserleaks.com/ip causes Midori to crash.
