1. “Anything you’ve made with Google Docs, Sheets, and Slides doesn’t count toward your storage limit.”1
2. Photographs stored at “High quality”.2
Google allows 2 options for storing your photographs —
● “High quality”, which will, “Save high-quality photos and videos while reducing size.”2 Photographs stored this way don't count against your free allocation.
● “Original”, “Stores your photos and videos exactly as you captured them.”2
Probably amounts to: “High quality” compresses images less than 16 megapixels with little or no loss. Larger images stored at "high quality" are reduced to 16 megapixels before compression.2
https://hhg2tech.blogspot.com.au/2015/03/how-to-maximise-your-free-storage-space.html
http://www.cnet.com/au/how-to/how-to-free-up-google-drive-space/
Thanks to Anne for this item.
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1 Google: "See your storage limit", https://support.google.com/drive/answer/6558?hl=en
2 Google: "Choose the upload size of your photos & videos", https://support.google.com/photos/answer/6220791 / Between Dropbox, Google Drive, OneDrive services cloud storage best ways to get extra free space service cloud storage provider promos extra storage space promotions new customers freebies providers bonus storage extra space invite a friend up to 16 GB extra storage adds 500 MB of space your account complete get started guide 250 MB bit of extra space install Carousel 3GB bonus for enabling auto upload your photos promo installing the Carousel app Android iOS install Mailbox 1GB similar promotion Mailbox app logging in once space permanently Apple store deauthenticate device link your Facebook Twitter accounts 125MB each social networks extra space little extra space connecting your accounts invite other users social sites device bonuses promotional offers 48GB of space for two years log in new Samsung HTC phone get more space page link check your personal account settings Google Drive your data syncing folders your desktop default 15GB upload data doesn’t count against your storage limit use play music store audio Play Music Google’s storage locker for your music bumped storage limit up to 50,000 tracks convert your documents Google Drive format Drive store your documents converting automatically convert documents upload Google Docs uploading crop photos below 2048×2048 upload an unlimited number of photos rule video below 15 minutes check your storage settings taking up space delete or convert some of your files purchase certain devices complete tasks Security Checkup promo Box 10GB of free storage basic plan pad that out OneDrive Microsoft’s OneDrive bonuses earn Camera Roll bonus link Office 365 subscription 1TB work school personal use refer a friend activated OneDrive backup photos with Camera Roll 3GB OneDrive app Android iOS Windows Phone automatically backup your pictures service enable disable integrated directly most-used desktop operating system sync unlimited space BitTorrent Sync service just launched 2.0 software folder workaround space on a server Amazon Cloud Storage Prime unlimited photo backup MEGA MegaUpload security end-to-end encryption Wuala breaks files into segments stores different servers combined over 100GB storage /