OneCal vs CalendarBridge: price, calendars and speed

OneCal and CalendarBridge are both paid calendar sync tools with booking links, a combined calendar view and an MCP server, and neither has a free plan. OneCal starts at $5 per user a month billed annually, connects any CalDAV server and allows up to 50 calendars per user. CalendarBridge starts at $4 a month billed yearly, limits plans by synced connections, and offers a HIPAA business associate agreement on its Premium and Pro plans. Keeper.sh, a calendar sync service, publishes this comparison; every OneCal and CalendarBridge figure below comes from their own pages, linked beside each figure.

What each one costs

OneCal prices per user, by the number of connected calendars: 2 on Starter, 5 on Essential and 50 on Premium. Billed annually, those plans are $5, $10 and $25 per user a month ($60, $120 and $300 a year). Billed monthly they are $6, $12 and $30. OneCal also offers an on-premise plan by enquiry (OneCal pricing).

CalendarBridge's individual plans are Basic, Premium and Pro. Billed yearly, they are $4, $8 and $32 a month and list 2, 5 and 8 calendars. Billed monthly, they are $5, $10 and $40 a month, and each monthly plan says "Add Unlimited Calendars". Every plan is also limited by synced connections: 2, 20 and 56 (CalendarBridge pricing). The CalendarBridge pricing explained page goes through those limits.

For 2 calendars, CalendarBridge Basic is the lower price on either billing period: $4 against $5 billed yearly, and $5 against $6 billed monthly. For 5 calendars, CalendarBridge Premium is $8 a month billed yearly and OneCal Essential is $10. For more than 8 calendars that all show each other's events, OneCal Premium is the plan that covers them, up to 50.

How their limits differ

OneCal counts calendars. Every plan includes "Unlimited Calendar Syncs" and both one-way and multi-way sync, so the plan you need depends only on how many calendars you connect.

CalendarBridge counts synced connections, each one copying events from one calendar to one other calendar. Its help centre works through the arithmetic: 3 calendars that all show each other's events need 6 connections, 5 calendars need 20, "which is what premium includes", and with 9 or more calendars "there is no way on an individual account to have all calendars reflect all other calendars" (how many sync connections do I need?, checked 10 November 2026).

Which calendars each one connects

OneCal supports "Google Calendar, Microsoft Outlook Calendar, Apple iCloud Calendar and any calendar server that supports CalDAV, such as Fastmail, Nextcloud or Zoho" (OneCal). It does not subscribe to .ics links directly: you subscribe to the link in Google Calendar or Outlook first and import that calendar, which can then be the source of a one-way sync (OneCal docs: ICS calendars, checked 10 November 2026).

CalendarBridge supports "Google Calendar, Microsoft 365 for Business, and Microsoft personal accounts (outlook.com, hotmail.com, live.com, and msn.com), and iCloud", and reads .ics links directly as a sync source for other providers (CalendarBridge). It also supports Microsoft 365 GCC High.

How fast each one syncs

OneCal says "The calendars sync automatically, in real-time" and gives no figure for Google and Outlook; "iCloud Calendar and CalDAV calendar updates take up to 10 minutes" (OneCal).

CalendarBridge says a change to a Google or Outlook source "typically propagates to the destination calendar within a minute", and that iCloud and .ics sources "sync every 5 to 10 minutes" (how often do calendars sync?).

What else each one includes

Both products have booking links, a combined calendar view, an AI assistant and an MCP server.

• OneCal: unlimited scheduling links, iOS and Android apps, sync filters by title, colour, hours, RSVP and event type, and an on-premise option for companies that need to run it on their own servers.
• CalendarBridge: up to 10 scheduling pages, payments for bookings through Stripe, an email-based AI scheduling assistant, a HIPAA business associate agreement on Premium and Pro, SOC 2 Type 1 and Type 2 reports, and group plans with one bill.

When OneCal fits

• One of your calendars is on Fastmail, Nextcloud or another CalDAV server.
• You have more than 8 calendars that should all show each other's events, without counting connections.
• You need more than 10 booking links.

When CalendarBridge fits

• You work in healthcare and need a signed HIPAA business associate agreement.
• Your organisation is on Microsoft 365 GCC High.
• You sync 2 to 5 calendars and want the lower published price.
• One of your sources is an .ics link you want read directly.

A third option: Keeper.sh

Keeper.sh is a calendar sync service that copies events between Google Calendar, Outlook, iCloud, Fastmail and any CalDAV server. Each copy is a busy block named after the source calendar. The title, description and location are hidden by default, Pro can turn them back on per calendar, and guest lists are never copied. Each connection runs one way, so two-way sync is two connections; the calendar sync features page lists what else each connection can do. The Free plan covers 2 calendar accounts and 3 connections, with changes landing every 30 minutes. Pro is $5 a month or $45 a year, with Google and Outlook changes landing within seconds and iCloud, Fastmail and CalDAV changes landing every minute (pricing).

The OneCal alternative and CalendarBridge alternative pages compare it with each product.

Step-by-step setup is in how to sync Google Calendar and Outlook and how to sync iCloud Calendar with Outlook.

Common questions about OneCal and CalendarBridge

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