ISP Data Cap + Library Sharing

Obviously media isn’t stored on Plex servers which makes me wonder… When my friends stream from my library what kind of impact will it have on the data allowance from my ISP?
Does plex have a transcoding protocol that keeps data transfer to a minimum? Or would I see extremely high data increases for something like a full 4k dts movie file?
I want to share my library with a few close friends in another state, but I have a 1TB cap and can easily see them wrecking it.
If anyone knows, even from personal experience, I’d love to hear your thoughts. Thanks everyone.

It does use your data limit. The best thing you could do is to limit the upload speed section… with this you can limit the upload speed to. 4 Mbps, or whatever…

You could also tell your friends what quality settings to use. This would reduce your data usage and the quality of their streams… But they would have to drop the quality settings themselves.

It largely depends on how many friends you have using Plex and how often they use it.

You can limit data usage for your friends
A few settings that can help.

Settings -> Remote Access --> Limit remote stream bitrate
Settings -> Transcoder --> Maximum simultaneous video transcode
Settings -> Transcoder --> Transcoder quality
*This may help a little in the size of the transcoded video.

Thanks for the replies. Both bits of info are exactly what I was looking for.

These are Plex Pass features.

This affects mainly the quality, not the size.

Transcoding an UHD 4K rip requires significant processing power. Your average computer can’t do it. (A NAS even less so)