Paste the iCal export link from Airbnb, Vrbo or Booking.com. We fetch it once, exactly the way the other platform does, and show you what it would import. Nothing is stored.
Airbnb: Calendar → Availability → Connect calendars → Export. Vrbo: Calendar → Import/Export → Export. Booking.com: Rates & Availability → Sync calendars.
BookingWarden checks your links every few minutes and texts you when a booking fails to carry across to another platform. One message when it breaks, one when it's fixed.
The link returns a real calendar file, not an error page or an empty document. Airbnb and Vrbo revoke export links when you reset them, and a revoked link fails silently on the importing side.
Airbnb exports guests as "Reserved" and everything else as "Not available". Vrbo uses "Reserved" and "Blocked". Booking.com labels both the same, so it can only report blocked nights. Dates imported from another platform show up as blocks, which is correct: that's what the other platform should see.
Whether the other platform has actually imported it recently. That needs a second link and a few hours of watching, which is what the full service does.