When comparing Seafile vs Sync, the Slant community recommends Seafile for most people. In the question“What are the best personal file-syncing solutions?” Seafile is ranked 5th while Sync is ranked 6th. The most important reason people chose Seafile is:
Seafile community edition is licensed under GPLv2 with source code available on [GitHub](https://github.com/haiwen/seafile).
Ranked in these QuestionsQuestion Ranking
Pro Free and open source
Seafile community edition is licensed under GPLv2 with source code available on GitHub.
Pro Client-side encryption
All files are transferred with AES 128 bit encryption.
Pro 5GB of free storage
250% more space than Dropbox basic plan.
Pro Privacy conscious
Terms and conditions favor user privacy.
Data is fully encrypted on the client-side, both in-transit and at-rest.
Pro Two-factor authentication
Even free accounts offer 2FA.
Con Requires maintenance
You have to manually keep the server and clients up to date.