Question: I've tried searching for the answer but couldn't find it. Do the notes stored in Google Keep use space from the Google storage? Or is it free and unlimited like a Google doc in Google Drive?

EDIT: that's too good to believe they would give unlimited storage for pictures and audio recordings.

Any update?

Answer: 
Tested this a minute ago: 19,999 characters is the upper limit for text in **each** Google Keep note, not including the title or any images. additionally, 999 characters maximum are allowed in the title. I was able to upload 7 images totaling 3.0MB to the same note after the above text limits were reached. I assume more images can be attached to the same note, but I stopped at 7.
As per the Google Product [forum answer](https://productforums.google.com/forum/#!topic/docs/_mgdBX6y53A;context-place=topicsearchin/docs/category$3Akeep$20storage$20space) no data attached to Google Drive account.