If you decide to self-host EteSync you won’t have to pay for the subscription. Tutorial here.
The self-hosting escape hatch is the real draw: run your own server and you skip the subscription entirely while keeping end-to-end encrypted, standards-friendly sync for calendars and contacts. The flip side is that development has gone quiet, so weigh that before committing your data to it. Good fit for technical users who want to own the server and value CalDAV-style compatibility. Less ideal if you want a hands-off hosted service with active development.
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EteSync alternatives
Free to use, even commercially. Changes must be published under the same license, and running a modified version as a network service counts as distributing it.
Permits
- Commercial use
- Modification
- Distribution
- Patent use
- Private use
Requires
- Disclose source
- Network use is distribution
- Same license
- State changes
- License and copyright notice
Does not provide
- Liability cover
- Warranty
Why it matters: The network clause is the point. Anyone who runs a modified version as a hosted service has to publish those changes, so the code handling your data stays inspectable. This is why privacy-first projects reach for AGPL.
Plain-language summary of the project's license, not legal advice. Read the full text for the exact terms.