CalSync is a free and open source alternative to OneCal, CalendarBridge, and Reclaim.ai. It syncs and merges events between local device calendars â no cloud servers, no accounts, no subscription.
When an event appears in one calendar, CalSync automatically copies it to another using a name you choose. All syncing happens directly on your device. Your calendar data never leaves your phone.
â FREE & OPEN SOURCE â No subscription, no hidden costs, no ads
đą WORKS OFFLINE â No internet connection required, ever
đ 100% PRIVATE â Calendar data stays on your device, period
đ¤ NO ACCOUNT â No signups, no logins, no personal info collected
đ AUTOMATIC BACKGROUND SYNC â Detects calendar changes within seconds
đ CUSTOM EVENT NAMES â Choose what synced events are called (e.g. "Busy")
đ SYNC PREVIEW â See exactly what will change before it happens
đī¸ DELETION MIRRORING â Remove an event from source, removed from target
đ RECURRING EVENTS â Repeat events stay in sync automatically
đ¨ MATERIAL YOU â Adapts to your device's dynamic color theme
Perfect if you need to:
âĸ Sync work and personal calendars to share availability
âĸ Prevent double-bookings across multiple calendars
âĸ Manage client calendars as a freelancer or consultant
âĸ Keep family calendars in sync without sharing login credentials
If you're looking for a OneCal alternative, CalendarBridge alternative, or Reclaim.ai alternative â CalSync is the offline, private, and completely free solution.
No ads. No tracking. No telemetry. Just calendar sync that works.
Versions
Although APK downloads are available below to give you the choice, you should be aware that by installing that way you will not receive update notifications and it's a less secure way to download. We recommend that you install the F-Droid client and use that.
Download F-Droid
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x86_64
This version requires Android 7.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Permissions
-
run foreground service
Allows the app to make use of foreground services.
-
show notifications
Allows the app to show notifications
-
Read calendar events and details
This app can read all calendar events stored on your phone and share or save your calendar data.
-
run at startup
Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
-
prevent phone from sleeping
Allows the app to prevent the phone from going to sleep.
-
add or modify calendar events and send email to guests without owners' knowledge
This app can add, remove, or change calendar events on your phone. This app can send messages that may appear to come from calendar owners, or change events without notifying their owners.
-
dev.henriquecouto.calsync.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK
18 MiB
PGP Signature
|
Build Log
-
arm64-v8a
This version requires Android 7.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Permissions
-
run foreground service
Allows the app to make use of foreground services.
-
show notifications
Allows the app to show notifications
-
Read calendar events and details
This app can read all calendar events stored on your phone and share or save your calendar data.
-
run at startup
Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
-
prevent phone from sleeping
Allows the app to prevent the phone from going to sleep.
-
add or modify calendar events and send email to guests without owners' knowledge
This app can add, remove, or change calendar events on your phone. This app can send messages that may appear to come from calendar owners, or change events without notifying their owners.
-
dev.henriquecouto.calsync.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK
17 MiB
PGP Signature
|
Build Log
-
armeabi-v7a
This version requires Android 7.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Permissions
-
run foreground service
Allows the app to make use of foreground services.
-
show notifications
Allows the app to show notifications
-
Read calendar events and details
This app can read all calendar events stored on your phone and share or save your calendar data.
-
run at startup
Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
-
prevent phone from sleeping
Allows the app to prevent the phone from going to sleep.
-
add or modify calendar events and send email to guests without owners' knowledge
This app can add, remove, or change calendar events on your phone. This app can send messages that may appear to come from calendar owners, or change events without notifying their owners.
-
dev.henriquecouto.calsync.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK
14 MiB
PGP Signature
|
Build Log
-
x86_64
This version requires Android 7.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Permissions
-
view network connections
Allows the app to view information about network connections such as which networks exist and are connected.
-
run foreground service
Allows the app to make use of foreground services.
-
show notifications
Allows the app to show notifications
-
Read calendar events and details
This app can read all calendar events stored on your phone and share or save your calendar data.
-
run at startup
Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
-
prevent phone from sleeping
Allows the app to prevent the phone from going to sleep.
-
add or modify calendar events and send email to guests without owners' knowledge
This app can add, remove, or change calendar events on your phone. This app can send messages that may appear to come from calendar owners, or change events without notifying their owners.
-
dev.henriquecouto.calsync.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK
18 MiB
PGP Signature
|
Build Log
-
arm64-v8a
This version requires Android 7.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Permissions
-
view network connections
Allows the app to view information about network connections such as which networks exist and are connected.
-
run foreground service
Allows the app to make use of foreground services.
-
show notifications
Allows the app to show notifications
-
Read calendar events and details
This app can read all calendar events stored on your phone and share or save your calendar data.
-
run at startup
Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
-
prevent phone from sleeping
Allows the app to prevent the phone from going to sleep.
-
add or modify calendar events and send email to guests without owners' knowledge
This app can add, remove, or change calendar events on your phone. This app can send messages that may appear to come from calendar owners, or change events without notifying their owners.
-
dev.henriquecouto.calsync.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK
17 MiB
PGP Signature
|
Build Log
-
armeabi-v7a
This version requires Android 7.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Permissions
-
view network connections
Allows the app to view information about network connections such as which networks exist and are connected.
-
run foreground service
Allows the app to make use of foreground services.
-
show notifications
Allows the app to show notifications
-
Read calendar events and details
This app can read all calendar events stored on your phone and share or save your calendar data.
-
run at startup
Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
-
prevent phone from sleeping
Allows the app to prevent the phone from going to sleep.
-
add or modify calendar events and send email to guests without owners' knowledge
This app can add, remove, or change calendar events on your phone. This app can send messages that may appear to come from calendar owners, or change events without notifying their owners.
-
dev.henriquecouto.calsync.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK
14 MiB
PGP Signature
|
Build Log
-
x86_64
This version requires Android 7.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Permissions
-
view network connections
Allows the app to view information about network connections such as which networks exist and are connected.
-
run foreground service
Allows the app to make use of foreground services.
-
show notifications
Allows the app to show notifications
-
Read calendar events and details
This app can read all calendar events stored on your phone and share or save your calendar data.
-
run at startup
Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
-
prevent phone from sleeping
Allows the app to prevent the phone from going to sleep.
-
add or modify calendar events and send email to guests without owners' knowledge
This app can add, remove, or change calendar events on your phone. This app can send messages that may appear to come from calendar owners, or change events without notifying their owners.
-
dev.henriquecouto.calsync.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK
18 MiB
PGP Signature
|
Build Log
-
arm64-v8a
This version requires Android 7.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Permissions
-
view network connections
Allows the app to view information about network connections such as which networks exist and are connected.
-
run foreground service
Allows the app to make use of foreground services.
-
show notifications
Allows the app to show notifications
-
Read calendar events and details
This app can read all calendar events stored on your phone and share or save your calendar data.
-
run at startup
Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
-
prevent phone from sleeping
Allows the app to prevent the phone from going to sleep.
-
add or modify calendar events and send email to guests without owners' knowledge
This app can add, remove, or change calendar events on your phone. This app can send messages that may appear to come from calendar owners, or change events without notifying their owners.
-
dev.henriquecouto.calsync.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK
17 MiB
PGP Signature
|
Build Log
-
armeabi-v7a
This version requires Android 7.0 or newer.
It is built and signed by the original developer, and guaranteed to correspond to this source tarball.
Permissions
-
view network connections
Allows the app to view information about network connections such as which networks exist and are connected.
-
run foreground service
Allows the app to make use of foreground services.
-
show notifications
Allows the app to show notifications
-
Read calendar events and details
This app can read all calendar events stored on your phone and share or save your calendar data.
-
run at startup
Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.
-
prevent phone from sleeping
Allows the app to prevent the phone from going to sleep.
-
add or modify calendar events and send email to guests without owners' knowledge
This app can add, remove, or change calendar events on your phone. This app can send messages that may appear to come from calendar owners, or change events without notifying their owners.
-
dev.henriquecouto.calsync.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION
Download APK
14 MiB
PGP Signature
|
Build Log
