progressbar snaping
This may or may not be a known issue, This happens for me on multiple browsers and multiple systems both on my site copy and your demo copy.
What is happening is the progress bars roll up to about 35-38% and then snap instantly to 100%
I've had a look around main.js but can't find anything that looks like a cause
I create a gif of what its doing for visual reference if needed

I was able to work around this by changing the following code on line 125 of main.js
size = size/1024/1024/2;' to 'size = size/1024/1024/5;
Something is wrong with the math, 5 = 1/2 of 10 but /2 isn't working properly, need a better way to divide size by 2
This would break again once the file sized rolled up to the next size, so not really a viable solution
The bars simply show the loaded portion of the download/upload data. Since the test library ends the transfer when it reaches a duration of 8 seconds the bar will simply snap to 100% after 8 seconds even if the transfer hasn't finished.
A possible solution is to change the logic behind the bar filling rate, in order for it to work properly we must use the loaded/size for transfers that finish prior the 8 seconds timeout and the seconds_passed/8secs for every other test. The problem here is that we don't know if a test will lasts 8 seconds or not.
Any suggestion is appreciated.
Hmm, Yeah i don't have any ideas yet, other than not depending on time and using rather some function to detect if the transfer has ended.
But with the library using a time-based system not sure this is really possible
Alternatively, perhaps increasing the time from 8 seconds to 10-15 seconds could alleviate most of this, it should give slower connections time to complete the test natively