Different bit rates and file sizes for same file

[TerryA cdc]

I downloaded a film from Netflix and it was 3.5 gb 5.1 mb/s. A few days later I downloaded the same film from Netflix and this time it was 9.1 gb 13.7 mb/s. A massive difference. Has anyone else found this? Do Netflix adjust the bit rate depending on server load or other factors?

[signals]

The services sometimes adjust it based on the device (browser, smartphone etc) and the Downloader looks like a browser to their servers in most cases.