Between the S8 Pro Ultra and Roomba j9+, the S8 Pro Ultra comes out ahead in mopping / 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 / 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 do not 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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