How Caltsu compares
What each tool writes into your other calendars, which providers it covers, what it costs and where its database is. Competitor details come from their public websites, checked September 2026.
- What the other calendar receives
CaltsuStart and end time, title Busy, and the source calendar's name. Never event details.
OneCalConfigurable. You choose which details are shown.
CalendarBridgeConfigurable. All details, Busy only, or in between.
Reclaim.aiCopied events. Details depend on sync settings.
Cal.comNothing. It reads calendars to check conflicts.
- Apple iCloud
CaltsuNot yet
OneCalYes
CalendarBridgeYes
Reclaim.aiNo
Cal.comYes
- Microsoft 365 and Outlook
CaltsuYes
OneCalYes
CalendarBridgeYes
Reclaim.aiYes
Cal.comYes
- Starting price
Caltsu€5 per month
OneCalFrom $5 per user per month for 2 calendars
CalendarBridgeFrom $5 a month for 2 synced connections
Reclaim.aiFree plan. Paid from $10 per seat per month
Cal.comFree for one person. Teams from $12 per user per month
- Database location
CaltsuFrankfurt, Germany
OneCalServers in the US
CalendarBridgeHosted in the US
Reclaim.aiSee their privacy policy
Cal.comTheir cloud, or self-hosted
| Topic | Caltsu | OneCal | CalendarBridge | Reclaim.ai | Cal.com |
|---|---|---|---|---|---|
| What the other calendar receives | Start and end time, title Busy, and the source calendar's name. Never event details. | Configurable. You choose which details are shown. | Configurable. All details, Busy only, or in between. | Copied events. Details depend on sync settings. | Nothing. It reads calendars to check conflicts. |
| Apple iCloud | Not yet | Yes | Yes | No | Yes |
| Microsoft 365 and Outlook | Yes | Yes | Yes | Yes | Yes |
| Starting price | €5 per month | From $5 per user per month for 2 calendars | From $5 a month for 2 synced connections | Free plan. Paid from $10 per seat per month | Free for one person. Teams from $12 per user per month |
| Database location | Frankfurt, Germany | Servers in the US | Hosted in the US | See their privacy policy | Their cloud, or self-hosted |
Side by side, one tool at a time
- Caltsu vs OneCalBoth copy events between calendars. OneCal also covers iCloud. Caltsu never copies event details.
- Caltsu vs CalendarBridgeBoth sync Google and Microsoft calendars. CalendarBridge adds iCloud, scheduling pages and an AI assistant. Caltsu only writes Busy blocks.
- Caltsu vs Reclaim.aiReclaim schedules tasks and habits with AI and includes calendar sync. Caltsu only syncs.
- Caltsu vs ClockwiseClockwise shut down in March 2026. Caltsu covers the personal calendar sync part.
- Caltsu vs Cal.comCal.com publishes booking pages. Caltsu makes every calendar show when you are busy.
What Caltsu does not do
Caltsu connects Google and Microsoft accounts only. Apple iCloud is not supported yet. Every calendar in a sync group both sends and receives Busy blocks. There is no one-way mode.
It has no booking pages and never moves or creates meetings. It only adds, updates and removes Busy blocks, so it works next to a scheduling tool rather than replacing one.
There is no team plan. Each person has their own account. To buy for a team or pay by invoice, email support@caltsu.com.