iRobot Roomba Plus 678 Combo
A strong pick for hard-floor homes that want hot-water roller mopping and a full-service dock for less than iRobot’s flagship 875.
Amazon $899.99$899.99
The iRobot Roomba Plus 678 Combo is the better robot vacuum overall, rated 3.9 to 3.2. The iRobot Roomba Plus 678 Combo leads on navigation and mopping. The iRobot Roomba Plus 405 Combo costs $100 less ($799.99 vs $899.99).
iRobot Roomba Plus 405 Combo
#103 in Self-cleaning dockFull review
Suits large, mostly hard-floor homes that want a self-washing mop dock from a familiar brand; weak carpet and pet hair results make it a poor fit for rugs and pets.
Amazon $799.99$799.99
Prices were last checked November 1, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the iRobot Roomba Plus 678 Combo for navigation (LiDAR + camera vs LiDAR) and mopping (Roller, lifts 10 mm, extends to edges vs Dual spinning pads).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every self-cleaning dock robot vacuum; a clear win is highlighted. How we rank explains each one.
| Factor weight | iRobot Roomba Plus 678 Combo | iRobot Roomba Plus 405 Combo |
|---|---|---|
| Overall rating | 3.9/5 | 3.2/5 |
| Cleaning 30% | 48 not yet tested; estimated from 3 tested iRobot robots and the median of the 70 tested robots | 11 measured 58% of sand from carpet, 49.5% of pet hair, some hair tangled (0.2) |
| Value 25% | 42 $900 | 50 $800 |
| Dock 20% | 100 Self-empties the bin, washes the mop, hot-water mop wash, hot-air mop drying, doses detergent | 87 Self-empties the bin, washes the mop |
| Navigation 15% | 100 LiDAR + camera | 65 LiDAR |
| Mopping 10% | 90 Roller, lifts 10 mm, extends to edges | 56 Dual spinning pads |
Independent tests
iRobot Roomba Plus 678 Combo
No independent test published yet.
iRobot Roomba Plus 405 Combo
| Tested by | Carpet deep clean | Pet hair | Hair tangle (0 = none) | Area per charge | Conditions |
|---|---|---|---|---|---|
| Vacuum Wars | 58% | 49.5% | 0.2 | 1,421 sq ft | Embedded sand in medium-pile carpet; flattened 2.5 in pet hair on carpet, two runs; 7 in hair tangle on hard floor (0 = none wrapped). |
Specifications
| iRobot Roomba Plus 678 Combo | iRobot Roomba Plus 405 Combo | |
|---|---|---|
| Vacuum | ||
| Claimed suction | 30,000 Pa | - |
| Main brush | hair-cutting multi-surface bristle brush | multi-surface rubber brush |
| Mopping | ||
| Mop | Roller, lifts 10 mm, extends to edges | Dual spinning pads |
| Mop lift | 10 mm | - |
| Leaves mop at dock | No | No |
| Extending mop | Yes | No |
| Dock | ||
| Dock | Washes mop + empties | Washes mop + empties |
| Self-empties | Yes | Yes |
| Washes mop | Yes | Yes |
| Hot-water wash | Yes | - |
| Hot-air drying | Yes | No |
| Detergent dosing | Yes | - |
| Navigation & app | ||
| Navigation | LiDAR + camera | LiDAR |
| Obstacle avoidance | PrecisionVision AI camera object recognition; SprayForce AI pre-treats detected stains | Object sensing (sensor type not given) |
| Climbs thresholds | 35 mm | - |
| Voice assistants | - | Alexa, Siri, Google Assistant |
| Build | ||
| Height | 3.9 in (99 mm) | 4.2 in (107 mm) |
| Battery | 6,000 mAh | - |
| Weight | 10.7 lb (4.8 kg) | 9.1 lb (4.1 kg) |
| Released | 2026-09 | 2025-03 |