Threshold climbing is the spec that keeps your robot vacuum from getting stuck on door transitions

Threshold climbing is one of those specs you don’t think about until your vacuum gets stuck on a door transition. It’s the robot’s ability to roll over raised strips — door frames, room transitions, that metal bar between tile and carpet — without beaching itself. Every model has a maximum climb height in millimetres, usually somewhere between 10mm and 20mm. Above that, you’re watching the little guy spin its wheels helplessly. Worth checking before you buy if your house has any thick thresholds.