Don't Double Book Me does one thing well: real-time sync between Google and Outlook calendars, with working hours and privacy templates. CalendarPipe covers Apple Calendar and ICS feeds too, runs your rules as JavaScript in a sandbox, delivers events as plain calendar invitations, and has a plan that's free forever.
Don't Double Book Mehas strengths, but here's what users run into.
Don't Double Book Me syncs Google and Microsoft Outlook only. Apple Calendar / iCloud is on their roadmap, not in the product — so if your personal calendar lives on iCloud, it can't be part of the sync.
You get working hours, time rounding, privacy modes, and title templates with {{title}} / {{description}} / {{location}} placeholders. That covers simple cases, but you can't filter by keyword or attendee, write conditional logic, or transform events with code.
Don't Double Book Me has no REST API, no webhooks for your own automations, and nothing for AI agents. It's a finished product, not a building block.
Don't Double Book Me gives you a 7-day free trial, then it's $20/year. There's no permanent free plan to fall back on when your needs are light.
Full Apple Calendar / CalDAV support, plus ICS feed subscriptions — not a roadmap promise. Google, Outlook, and Apple are all first-class in CalendarPipe.
Write JavaScript gate functions that run in a secure sandbox: filter events by any field, rewrite titles, strip attendees, route conditionally, skip weekends. Prefer not to code? Use the visual builder or describe the rule in plain English.
CalendarPipe's free plan never expires — 2 calendars, 1 sync rule, no time limit. Don't Double Book Me gives you 7 days, then it's pay or leave.
A REST API and an MCP server for AI agents. CalendarPipe can even host calendars an AI agent owns outright — its own address, driven by the API. There if you ever need it.
CalendarPipe vs Don't Double Book Me — side by side.
| Feature | CalendarPipe | Don't Double Book Me |
|---|---|---|
| Google Calendar | ||
| Outlook / Microsoft 365 | ||
| Apple Calendar / iCloud | ||
| ICS / internet calendar feeds | ||
| Programmable sync rules (JavaScript) | ||
| Event filtering & transformation | Full (JS sandbox) | Working hours & templates |
| Invitation-based delivery | ||
| REST API | ||
| MCP server for AI agents | ||
| Free-forever plan | ||
| Real-time webhook sync | Every 5 min (Pro) | |
| Booking / scheduling links |
What you pay — and what each plan actually gets you.
Personal
Unlimited syncs · Google & Outlook · 1-week trial
Team
Minimum 3 seats · consolidated billing · priority support
No free plan — 1-week trial only.
Free
2 calendars · 1 sync rule · free forever
Pro
Unlimited calendars & rules · $3.33/mo billed annually
Free forever, or a 14-day Pro trial.
Don't Double Book Me is cheaper if two Google or Outlook calendars are all you sync. CalendarPipe is free to start, adds Apple and code-level rules, and only costs more when you need more.
There's no data to move and no hard cutover. Run CalendarPipe alongside Don't Double Book Me, then switch over only once you're ready.
CalendarPipe and Don't Double Book Me don't conflict. Keep Don't Double Book Me running while you set CalendarPipe up and test it — there's no rush to switch.
There's no data migration. CalendarPipe reads from the calendars you connect, so your events stay where they are. You're recreating sync rules, not moving data.
Connect your calendars, pick a template or describe a rule in plain English, and you're syncing. Cancel Don't Double Book Me once CalendarPipe does what you need.
Common questions about switching from Don't Double Book Me.
Two minutes to set up. Free forever plan, no credit card. Or try Pro free for 14 days.