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Avum vs Other Calendar Sync Tools: Side-by-Side Comparisons
Calendar sync tools look alike on their homepages. The differences show up in three places: what the plan limit actually counts, which calendars you can connect, and how much control you get over what is copied. This page puts the main dedicated sync tools side by side, then points you to a detailed comparison for each one.
Published by Avum. Prices and features were checked against each vendor's official pages on November 2, 2026.
Dedicated calendar sync tools compared
| Avum | OneCal | CalendarBridge | SyncThemCalendars | |
|---|---|---|---|---|
| Price | ||||
| Entry plan | $5 / month | $6 / month | $5 / month | $47.88 / year |
| Largest individual plan | $10 / month | $30 / month | $40 / month | $215.88 / year |
| Free trial | 30 days | 14 days | 14 days | 14 days |
| What the plan counts | ||||
| Unit | Accounts and rules | Calendars | Calendars and one-way connections | Two-way calendar pairs |
| Calendars on the largest plan | No limit inside 10 accounts | 50 | 8 | Unlimited, 36 syncs |
| Calendars | ||||
| Google, Outlook and iCloud | Yes | Yes | Yes | Yes |
| CalDAV servers | Yes | Yes | Yes | Not listed |
| ICS feed as a direct source | Yes | Via Google or Outlook | Yes | Not listed |
| Control | ||||
| Hide private details in copies | Yes | Yes | Yes | Yes |
| Filter by weekday, hour or date range | Yes | Not advertised | Not advertised | Not advertised |
| Formula or JavaScript transforms | Yes | Not advertised | Not advertised | Not advertised |
| Extras | ||||
| Booking links | No | Yes | Yes | Not listed |
| AI scheduling assistant | No | Yes | Yes | Not listed |
Monthly prices are for monthly billing, except SyncThemCalendars, which is shown at its published yearly price. All prices are in US dollars for one user. Sources are linked in each detailed comparison.
Avum is the least expensive of the four at the top end and offers the longest trial. It is also the only one of the four that advertises direct ICS sources, CalDAV and time-based filters together. OneCal and CalendarBridge include booking tools that Avum does not.
Detailed comparisons
Calendar sync services
- Avum vs OneCal. OneCal charges per calendar; Avum charges per account. For a consultant with eight calendars across four accounts, that is $7 a month against $30.
- Avum vs CalendarBridge. CalendarBridge counts every sync direction separately. Three calendars that all block each other use six connections.
- Avum vs SyncThemCalendars. A simple, low-cost mirror for Google, Outlook and iCloud, without CalDAV, ICS sources or event filters.
- Avum vs SyncGene. SyncGene is moving to CiraHub. If you only used it for calendars, here is what to check before you switch.
A free desktop utility
- Avum vs Outlook Google Calendar Sync. OGCS is free and open source, but it runs on your computer and covers Google and Outlook only.
Planning and scheduling tools
- Avum vs Reclaim. Reclaim plans tasks and habits with AI. Its free plan includes a single calendar sync.
- Avum vs Morgen. A daily planner with calendar propagation, at $15 to $30 a month.
- Avum vs Calendly. Calendly books new meetings. It does not put your personal appointments on the work calendar your coworkers check.
- Avum vs Calendar.com. A scheduling suite with analytics, compared with a focused sync tool.
How to choose in five minutes
- Count accounts and calendars separately. Three accounts can easily contain eight calendars. A tool that charges per calendar or per direction can cost several times more than one that charges per account.
- List every calendar type. If a timetable, rota, Fastmail or Nextcloud calendar is involved, check for ICS and CalDAV support first.
- Decide what the destination should see. Most people want personal appointments to appear at work as “Busy” with no title, notes or location.
- Decide whether you need booking pages. If you do, compare the suites. If you only need your calendars to agree, a focused tool usually costs less.
- Test with your real calendars. Create, move, repeat and cancel a test event. The calendar sync test checklist lists each step.
Not sure whether you need sync at all? Calendar sync, sharing and subscriptions explains when a native option is enough.