Between the S8 Pro Ultra and Roomba j9+, the S8 Pro Ultra comes out ahead in mopping and lidar, while the Roomba j9+ wins on battery life. Overall, the S8 Pro Ultra scores 57.7 and the Roomba j9+ scores 49.8 on our Mars Score.
Which should you buy?
The S8 Pro Ultra edges ahead on the Mars Score (57.7 vs 49.8), but the 7.9-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the S8 Pro Ultra if you care most about mopping and lidar. The biggest gaps in its favor are mopping, lidar, noise, among others.
Pick the Roomba j9+ if you care most about battery life. Its strongest claims are battery life.
Both ship with comparable self-empty base, ai obstacle avoidance, so those specs don't separate the two — focus on the differences below.
Bottom line: the S8 Pro Ultra is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Roborock - S8 Pro Ultra wins
- ▲Has Mopping.
- ▲Has Lidar.
- ▲Noise — 1.00 dB less. 67 vs 68.
- ▲Suction: 6000 Pa vs 0 Pa.
- ▲Water tank: 180 ml vs 0 ml.
Why iRobot - Roomba j9+ wins
- ▲Battery life — 11.11% more. 200 min vs 180 min.
Spec comparison
Cleaning
| Spec | Roborock - S8 Pro Ultra | iRobot - Roomba j9+ |
|---|---|---|
| Suction | 6000 Palead | 0 Pa |
| Mopping | truelead | false |
| Water tank | 180 mllead | 0 ml |
| Dustbin | 400 ml | 500 mllead |
| Carpet detection | true | true |
Navigation
| Spec | Roborock - S8 Pro Ultra | iRobot - Roomba j9+ |
|---|---|---|
| Lidar | truelead | false |
| Camera navigation | true | true |
| AI obstacle avoidance | true | true |
| Max climb | 20 mm | 20 mm |
Autonomy
| Spec | Roborock - S8 Pro Ultra | iRobot - Roomba j9+ |
|---|---|---|
| Battery life | 180 min | 200 minlead |
| Self-empty base | true | true |
| Self-wash mop | truelead | false |
| Self-dry mop | truelead | false |
| Noise | 67 dBlead | 68 dB |
Frequently asked
Which has stronger suction, S8 Pro Ultra or Roomba j9+?+
S8 Pro Ultra delivers 6000 Pa vs 0 Pa.
Do S8 Pro Ultra or Roomba j9+ mop?+
S8 Pro Ultra mops; Roomba j9+ vacuums only.
Which has a self-emptying base, S8 Pro Ultra or Roomba j9+?+
Both ship with a self-emptying base.
Spec-level deep dives
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