Fit and navigation
Measure low furniture before you buy
Low furniture is one of the simplest ways to rule out a robot before looking at app functions or suction claims. The robot must fit beneath the obstruction for its entire travel path, including the highest fixed part of its navigation hardware. Measure a real opening in several places rather than relying on the furniture's advertised leg height.
Measure the narrowest repeatable gap
Use a rigid ruler or a small height gauge to measure from the actual floor to the lowest point the robot would pass beneath. Check near each leg and across the middle; a sofa frame or bed rail can sag. Include carpet or a floor mat if it will remain in place, and account for a lip that a robot must climb before reaching the opening. If the gap changes with a removable rug, measure both configurations and decide which one will be in daily use.
Compare the measurement with the complete robot height. The original Roborock Qrevo Curv is 4.1 inches tall; the Qrevo Curv S5X is listed at 3.9 inches; and the CurvX is 3.14 inches with retractable LiDAR. The S5X is only a little lower than the original, while CurvX can open a lower route. Even a 3.14-inch body needs spare clearance for floor variation, rugs and soft material.
Do not mix height with threshold ability
Robot height and threshold clearance solve different problems. A low body may fit under a cabinet but still have trouble crossing a tall track. A liftable chassis may climb some raised transitions without lowering the top of a fixed sensor. Measure both the opening above the robot and any lip on the floor. Manufacturer maximum threshold figures should not be treated as guarantees for an unusual approach angle, soft mat or divided track.
Check the manual as well as the product comparison. Navigation details can change the available headroom, and a marketing feature does not override the physical dimension. If a passage is essential, confirm the exact model's full height and consider ordering through a retailer with clear return terms. Do not assume that a model with a similar name uses the same turret or dock.
What if the robot cannot reach?
Map a boundary or no-go area if the robot may wedge under a piece of furniture. A no-go setting can prevent a failed route, but it cannot clean the space it excludes. A lower robot may be a better fit if the route is important; a manual vacuum or a changed furniture layout may be more practical when no robot offers a safe margin. Use the finder to apply a height requirement, then compare the Curv, Curv S5X and CurvX reports.