Why is Safari restricted from using the service?

[RA80533]

It appears that Safari is functionally compatible with the website once the Safari-specific restrictions are removed. Is there a particular reason why the browser is prevented from using the service?

Safari 14.0.3

[robertodauria]

There seems to be a bug in the Webkit implementation of websockets preventing the message scaling algorithm to work properly, which results in upload measurements failing on some combinations of machine speed + connection speed. Further details: m-lab/ndt7-js#19 (comment)

There is also a different issue in the download measurement, so that it never reports more than ~500 Mb/s in our testing -- only on Safari.

While it would appear that the measurement is running just fine on Safari (and in most cases, i.e. < 500Mb/s, this is probably true), some percentage of measurements done on Safari will either fail while showing unreasonably high upload rate to the user (first bug), or under-report the download speed (second bug).

We decided to disable it until either we have a good workaround for these two issues, or they are fixed in Safari.