I have around 4TB cloud storage free. As my data is crossing my physical storage limit, currently this is the only way for me to store the old files which I do not touch regularly (as I am reluctant to buy a new storage device). I have found the following services which offer free storage of considerable amount:
- 4shared: 15GB free. Upload size limit per file is 2GB. Files get deleted automatically if no login for 180 days. 4shared has native clients for all major mobile and desktop platforms.
- ADrive: Offers 50GB free.
- Box: Comes up with 25GB or 50Gb free offers now and then.
- Copy: Virtually unlimited introductory offer! Grows in GBs. A 2.6TB account here.
- Dropbox: Pretty well-known cloud service.
- Flickr: Now 1TB for your photos. Enough for a lifetime!
- Google Drive: 15 GB to store and edit all your documents.
- MediaFire: Unlimited free space. There is a time limit before file deletion but you get multiple notifications via email before deletion. Only logging-in to MediaFire is enough to prevent files from deletion.
- Mega: 50GB free for sign-ups now. Claims full encryption.
- Minus: Space increases with accepted referrals. For images only.
- pCloud: 20GB is the limit for free accounts. But it has two incredible features.
- SkyDrive: For old users it used to provide 25GB (which I still have) but now it is offering 7GB for new sign-ups.
- Symform: 10GB for free with additional cloud storage in exchange of local storage. Patented RAID-96™ technology for security.
50GB through LifeHacker(offer expired). Fully encrypted. Ubuntu One: Offers 5GB for free. You can add another 20GB via referrals. If you are using Ubuntu this is also a great option. Supports music streaming. Though closely tied to Ubuntu it has clients for Android, Mac and Windows. Discontinued. Yunio: 1TB initially that grows by 1GB each day.
100GB free for first million sign-ups(offer expired).
I wouldn’t recommend storing sensitive data in the cloud for security and privacy. And it’s safe to have at least a backup copy of the same data in another cloud service. You always have a better chance of data recovery.