EteSync - Secure Data Sync

4.3
387 reviews
10K+
Downloads
Content rating
Everyone
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About this app

Secure, end-to-end encrypted, and privacy respecting sync for your contacts, calendars, and tasks (using Tasks.org and OpenTasks). For notes, please use the EteSync Notes application.

In order to use this application you need to have an account with EteSync (paid hosting), or run your own instance (free and open source). Check out https://www.etesync.com/ for more information.


Easy to Use
===========
EteSync is very easy to use. It seamlessly integrates with Android so you won't even notice you are using it. Security doesn't always have to come at a cost.

Secure & Open
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Thanks to zero-knowledge end-to-end encryption, not even we can see your data. Don't believe us? You shouldn't, just verify yourself, both the client and server are open source.

Full History
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A full history of your data is saved in an encrypted tamper-proof journal which means you can review, replay and revert any changes you have made at any point in time.


How does it work?
===============
EteSync integrates seamlessly with your existing apps. All you need to do is sign up (or run your own instance), install the app, and enter your password. After that, you will be able to save your contacts, calendar events and tasks to EteSync using your existing Android apps, and EteSync will transparently encrypt your data and update the change journal in the background. More security, same work-flow.
Updated on
Sep 19, 2025

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
No data shared with third parties
Learn more about how developers declare sharing
This app may collect these data types
Personal info, Calendar, and Contacts
Data is encrypted in transit
You can request that data be deleted

Ratings and reviews

4.4
381 reviews
Alicia Sykes
June 30, 2020
One t set up, EteSync works really well, you don't even notice it's there. It's considerably more private and secure than using Google Calendar, or another mainstream unencrypted provider. You can use almost any calendar app with it (I use SimpleCalendar, which is open source and works well). EteSync is 100% definitely worth spending a couple dollars on, or installing on your home server. I recommend it to all my friends, 5 Stars
33 people found this review helpful
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Kaine Inja
November 30, 2020
I want to like this app on principle, but it just doesnt work properly for me. Set up and initial sync of contacts seems to work fine, can see in contacts app, but after some time the contacts app just shows an empty address book even tho the sync journal shows the contacts have synced & should be there. I have tried clearing data, reinstalling, same thing happens every time. I use a self hosted server rather than the paid service, so maybe this app just doesnt work so well with custom servers.
32 people found this review helpful
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Tengu
November 30, 2020
Sorry to hear about your issue! This is definitely not how it should work. It has nothing to do with using a self-hosted server as those are essentially identical to the hosted ones. Please come to the chat at https://www.etesync.com/community-chat/ we would be happy to help figure out what's wrong!
Damian Królik
December 31, 2021
Maybe I just wasn't patient enough, but I just needed a simple app for notes sharing and I couldn't make it work with EteSync Notes - e.g. I don't understand how collections in EteSync are related to task lists in EteSync Notes but they are not in sync. Perhaps it is just my ignorance, but I expect a more intuitive workflow for such a simple job.
8 people found this review helpful
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What’s new

* Remove unused READ_MEDIA_IMAGES permission.
* Fix build with latest Android SDKs
* Bump target SDK