Roomba J7+ vs. S9+

Roomba J7 vs S9

We’ll be looking at two Roomba products in this comparison: the J7+ and S9+.

These models are some of the more innovative Roomba options. The S9+ was the first with the D-shape frame and wide (9-inch) extractors, and the J7+ is the first with a front-facing camera, enabling it to avoid obstacles (better than any obstacle-avoiding robot I’ve tested).

But which of these options are better? I’ve spent many days testing these products in various aspects to find out.

Let’s look at an overview of these products – a snapshot of the test results and product specifications.

Overview of the Roomba J7+ vs. S9+

Roomba J7+

Airflow: 7.27 CFM 📝 Sand on Hard Floor: 98.46% 📝 Deep Cleaning: 85.7%
Side brush: One 📝 Brush roll: Dual rubber extractors
Navigation: Front Camera + Gyroscope + Optical Sensor 📝 Map saving: Yes 📝 Number of maps: 10 📝 Containment: Yes 📝 Selective Room cleaning: Yes 📝 Recharge & Resume: Yes
Self-Empty: Yes 📝 Bag capacity: 2.4 liters 📝 Dustbin capacity: 400 ml
Mopping: No 📝 Pad Washing: No 📝 Clean water tank capacity: N/A 📝 Dirty water tank capacity: N/A 📝 Water tank (inside robot): N/A
Battery: 2410 mAh Li-ion 📝 Run time: 90 minutes 📝 Noise: 63 dB

Roomba S9+

Airflow: 25 CFM 📝 Sand on Hard Floor: 100% 📝 Deep Cleaning: 93%
Side brush: One 📝 Brush roll: Dual rubber extractors
Navigation: Top Camera + Gyroscope + Optical Sensor 📝 Map saving: Yes 📝 Number of maps: 10 📝 Containment: Yes 📝 Selective Room cleaning: Yes 📝 Recharge & Resume: Yes
Self-Empty: Yes 📝 Bag capacity: 2.4 liters 📝 Dustbin capacity: 500 ml
Mopping: No 📝 Pad Washing: No 📝 Clean water tank capacity: N/A 📝 Dirty water tank capacity: N/A 📝 Water tank (inside robot): N/A
Battery: 3200 mAh Li-ion 📝 Run time: 90 minutes 📝 Noise: 63 dB

* If you click this link and purchase, we earn a commission at no additional cost to you.

Introduction to the Roomba J7+ and S9+

Roomba products have evolved through the years.

The earlier variants were mostly inefficient robots that wandered around randomly until iRobot released the 980 (with VSLAM).

Then came the I7: the first iRobot with a self-emptying feature.

The Roomba S9+ is the best performing iRobot product (in terms of cleaning performance) thanks to its square front, wide extractors, and high-powered motor.

Roomba J7 vs S9 with clean base station

Lastly, the J7+ adds another layer of technology with its front-facing camera, allowing it to avoid obstacles.

But strangely (at least for me), iRobot reverted to the round frame and low airflow motor, affecting its cleaning performance.

Best-In-Class Vacuuming Performance

Roomba S9 with base station


  • Best-in-class vacuuming performance (on hard floors and carpets)
  • Efficient debris pick-up thanks to the wide extractors
  • Decent-sized dustbin
  • Excellent at cleaning embedded dirt on mid-pile carpet.


  • Short run time
  • Very noisy
  • Inefficient navigation (versus LIDAR robots)

The Roomba S9+ is, by far, the best performing robot vacuum if you look at vacuuming performance.

No other brand comes close to it with debris pick up.

It has the rare combination of agitation and airflow, enabling it to pick up more debris per pass.

Combining that with the wide extractors, the S9+ will be the most efficient (on a per pass basis). And much better than the Neato D8 I’ve tested recently.

Roomba S9+ extractors

Thus, when iRobot reverted to the round-frame with the J7, I was surprised since the square-front is a proven framework for excellent cleaning performance.

Other than the Roomba 980, no other robot vacuum comes close.

However, there are issues with the S9+, particularly navigation.

iRobot’s VSLAM algorithm, though more intelligent than its entry counterparts, isn’t perfect.

Its reliance on light and the use of an optical sensor has its limitations.

The most obvious is the lack of precision compared to a laser robot.

Also, the square front tends to wedge itself in tight spots, and iRobot says navigation efficiency is one reason it reverted to the round frame.

Another issue with the high-powered motor is the reduced run time. The S9 runs for only 75 minutes in the lowest setting and 45 minutes at the max.

I wouldn’t recommend this for large homes, even with recharge and resume.

Still, the Roomba S9+ is an excellent option for consumers who value cleaning performance and don’t mind the extra noise, short run time, and other quirks.

Best Obstacle Avoiding Robot: Roomba J7+

Roomba J7 w/ clean base station


  • Excellent at evading obstacles (pet feces, wires, shoes, etc.)
  • It has a slot in the clean base station for an extra bag
  • Auto-empty feature
  • Not very noisy
  • Low profile design will fit underneath low clearance furniture


  • Weak airflow
  • The clean base station is noisy
  • It doesn’t clean as well as the S9+

After the S9+, I’ve wondered what iRobot would come up with next, and it didn’t take long to find out with the Roomba J7+.

iRobot reverted to the round frame, realigned the clean base station, took off the IR sensor, and moved the camera to the front.

According to Spectrum.IEEE, iRobot went back to the round frame to make it more efficient.

And the J7 is better at traversing through tight quarters than iRobot’s entry-level options: the 600-series and E-series.

However, it still struggles with efficiency because it uses a camera sensor.

It’s the same issue as the S9+ – missed spots and indecisiveness on tight spaces.

Nonetheless, this is an issue with camera-based robots, not just the J7 and S9.

The biggest J7 advantage over the S9 is avoiding obstacles with the front-facing camera.

Roomba J7 front camera

It’s (perhaps) the best at evading objects thanks to its algorithm that’s smart enough not to get too close.

The J7 avoided pet feces and stretched out wires without touching them.

This feature is backed by a POOP guarantee (or Pet Owner Official Promise).

The guarantee states that if the J7 touches any dry feces, iRobot will replace it for free.

Unfortunately, this variant has the same motor as the I-Series: a weaker sub-10 CFM, low airflow engine.

Expect the same cleaning performance as the I3 and I6: though it’s better than the two, based on tests.

The J7 is an excellent option for folks who have pets or don’t want to move wires, expecting the robot to evade them.

It won’t clean like the S9 or the 980, but good enough for daily cleaning tasks.

Similarities Between the Roomba J7+ and S9+

We’ll look at the similarities between the Roomba J7 and S9 in this section.

1. Self-Emptying Feature

Both products have a clean base station, emptying the robot’s dustbin after every run.

The J7 and S9 use the same bag despite the cosmetic variance, which I like since availability won’t be an issue.

These bags have (approximately) a 2.4-liter capacity that iRobot says will last for (up to) 60 days.

However, the duration will depend on usage frequency and environment (or what debris the robot needs to clean daily).

2. VSLAM Algorithm

Ever since iRobot launched its smart robot lineup, they’ve relied on the VSLAM or Visual SLAM algorithm.

It means it utilizes a camera sensor and SLAM as the robot’s brains for navigation.

This feature is similar to Google’s self-driving car and provides these robots with smarts to traverse, track location, and dock independently.

3. Counter-Rotating Extractors

The J7 and S9 utilize iRobot’s patented counter-rotating extractors with varying lengths.

Roomba J7 and S9 extractor comparison

These rollers are excellent at agitation and help Roomba products to thrive at debris pick-up, even with low airflow.

4. iRobot Home App

Roomba J7 mapping run

Both models are compatible with the iRobot Home app. And consumers will need to download it to unlock all the features.

This app provides access to various features like keep-out zones, clean zones, scheduling, and much more.

I’ll discuss in detail the similarities and variances with these apps in another section below.

Differences between the Roomba J7 and S9

Next, we’ll look at the variances with both robots.

1. Shape

Roomba J7 vs S9 shape

The most obvious variance is the frame. The Roomba S9 has a D-shape frame and remains the only Roomba product with this design.

I thought (initially) that iRobot would make this change permanent with succeeding models, but with the J7’s release, that’s not the case.

iRobot prioritized navigation efficiency over cleaning efficiency when it reverted to the round frame of the J7.

One advantage of the S9’s square front is its debris pick-up efficiency. Combined with the high airflow, it vacuums more debris per pass than any other model I’ve tested.

But its biggest disadvantage is it struggles navigating through tight areas, especially office chair legs.

2. Side Brush and Extractor Design

Roomba J7 vs S9 underneath

The shape variances mean both utilize a different roller and side brush design, with the S9 having wider extractors than the J7.

Side brush placement is another difference due to the shape.

Roomba J7 vs S9 side brush

The S9 uses a five-prong side brush at the edge, giving it superior edge-cleaning performance over the J7.

It doesn’t spin as rapidly, so it won’t scatter as much debris – advantage S9.

The J7’s extractors and side brush are similar to the Roomba I3 and I6.

And expect the same issues present in the other two Roomba products I’ve mentioned above.

These include the fast-spinning side brush scattering debris and less efficient debris pick-up.

3. Dustbin Placement and Volume

Roomba J7 vs S9 dustbin

The J7 and S9’s dustbin have varying designs, placement, and volume. 

The J7’s dustbin is smaller (400-ml) with a rear-mounted placement, while the S9 is larger (500-ml) with a top-mounted placement.

Roomba J7 and S9 dustbin placement

Another variance is how these dustbins open. The S9 opens from the top, providing lots of access for cleaning, and the J7 has a front door, which is more cramped.

Roomba J7 and S9 opening

4. Camera Placement

Roomba J7 and S9 camera placement

Another variance is the camera placement. With the J7’s priority on obstacle avoidance, iRobot moved the camera to the front.

Initially, I thought iRobot retained the same top-mounted camera in the J7, but that’s not the case.

The front-facing camera doubles as a navigational sensor similar to the S9’s top-mounted camera: a reason why it’s slightly angled upward.

5. Clean Base Station

Roomba J7 and S9 clean base comparison

iRobot tweaked the J7 clean base station. Instead of utilizing the slim, tall frame in the older variants, they widened it and chopped off a good chunk from its vertical stance.

This change doesn’t affect the horizontal footprint much since it doesn’t exceed the robot’s diameter.

The redesign also allowed iRobot to add a slot for storing an extra bag.

It also has this leather tab, a nice touch helping consumers open the top door.

6. IR Sensor

I noticed iRobot removing the IR-sensor in the J7. It’s significant (at least for me) because it reduces front its vertical footprint, enabling it to go under lower clearance furniture than the S9 or I6.

Roomba J7 under sofa

The difference isn’t much, but every centimeter helps in this aspect.

App Features

These robots are compatible with the iRobot Home app, and we’ll look at the features set.

The Roomba S9 and J7 share many features with slight variances.

1. No Live Map [Both]

One feature lacking with the iRobot app is the live app. It only shows a robot graphic during the run.

So there’s no way of knowing where the robot is during the run.

But it does show maps of previous cleaning cycles in the history tab.

2. Map Saving [Both]

Roomba J7 map saving

What I like most about the iRobot app is its map-saving feature because it can save up to 10 levels.

Folks can customize each map level: add keep-out zones, clean zones, custom names, and more.

There’s no difference between the two variants in this category.

3. Keep-Out Zones [Both]

Roomba J7 no-go zones

One most helpful customization is the keep-out zone. It’s iRobot’s primary containment feature, blocking off-limit areas using virtual boxes on the app.

Consumers can add multiple zones as needed in areas they don’t want the robot to enter.

Unfortunately, the iRobot app doesn’t have an equivalent to the invisible wall feature (in other brands), and it can’t obstruct diagonal areas.

4. Clean Zones [Both]

Roomba J7 clean zone

One neat feature of the iRobot app is clean zones. These are opposite keep-out zones that specify “clean” spots or specific vacuuming areas.

It’s an inverted version of keep-out zones wherein these boxes are assigned clean areas.

None of the other apps have this feature, and it helps specify high-traffic zones.

5. Custom Room Naming [Both]

Both apps have a custom room naming feature, allowing users to specify any name they want.

This feature is usable with Alexa, adding another convenience layer for consumers.

6. Selective Room Cleaning [Both]

Roomba S9 selective room cleaning

Using VSLAM unlocks the selective room cleaning feature, meaning these robots can vacuum a specific room or area.

The custom naming also enhances this feature since you’re in control of the naming.

7. Robot Settings [Both]

Consumers can control settings like suction and thoroughness.

However, there are slight variations. Only the S9 app can adjust settings (up to three options) absent in the J7 since it has only one suction setting.

Here’s a screenshot of the S9 options.

Roomba S9 cleaning preferences

Next, the screenshot of the J7 options.

Roomba J7 cleaning preferences

And consumers can turn on/off the obstacle avoidance feature.

8. Obstacle Areas [J7 only]

Roomba J7 obstacle database

The obstacle area is a unique feature to the J7, enabling users to specify if the object is a permanent or temporary obstacle.

If you select the permanent option, the app automatically creates keep-out zones.

Roomba J7 keep-out from obstacles

9. Robot Health [J7 only]

Roomba J7 robot health

Another J7 feature absent in the S9 is robot health. It’s something new iRobot implemented and shows the status of the filter, side brush, and extractors when to replace them.

This tab also provides quick access to how-to articles for replacing these parts.

Roomba J7 robot health

Navigation Comparison

There isn’t much difference with the navigation. Both robots will move in what iRobot calls “neat rows.”

Since both use VSLAM, these will rely heavily on light to function.

One downside of using a camera sensor is its inefficiency, as both robots took over 30 minutes to complete the run in my small room.

However, thanks to the wide extractors and high airflow, the S9+ is more efficient with how much dirt it vacuums per pass.

In comparison, the J7 isn’t as proficient with the narrow rollers and weak airflow.

The advantage in this category goes to the S9.

Coverage Comparison

Again, the S9’s broader extractors and superior airflow allow it to gather more debris during the coverage test.

It got more quaker oats per pass and nearly got everything after the first pass. 

Sure, there are some missed spots, but it’s much less than the J7.

If you value efficiency, the S9 is the better alternative.

Airflow Comparison

Power setting
Roomba S9+
Power setting
Roomba J7+
11.33 CFM
7.27 CFM
14.52 CFM
25 CFM

One huge advantage for the S9 is airflow. I used an anemometer to measure this stat for all the robot vacuums I tested, and the S9 has the highest (so far) at 25 CFM.

The J7 utilizes the same motor as the I-Series, so it wasn’t surprising to see the sub-par result (only 7.27 CFM).

This airflow disparity shows itself in the cleaning test (next section), where the S9 performed much better.

Cleaning Comparison

Roomba S9+
Roomba J7+
Hard Floor
Sand on hard floor
Carpet (Surface Pickup)
Carpet (Deep Cleaning)

As you’ll see in the table above, the S9’s superior airflow means much better cleaning performance.

It scored higher across the board, both surface and embedded dirt experiments.

The wide extractors and high airflow are huge reasons it performed much better.

Also, the slower spinning side brush didn’t scatter as much debris, giving it better efficiency in this category.

I’d recommend this for homes with (a lot of) carpets since it excels at cleaning embedded dirt, posting the highest score (93%).

Which is better on hard floors?

The results above clearly show that the S9 is better on hard floors. It picked up a few percentage points higher across all the tests.

It may not sound a lot, but the eye test reveals that the S9 had much cleaner passes, fewer scattered debris, and better proficiency.

Another sign of its superior hard floor performance is its sand on hard floor scores at 100%.

The S9 gobbled up pretty much every crumb of sand I scattered without minimal buildup on the brush assembly.

Roomba S9 sand on hard floor

This variant is an excellent alternative for folks who live in a sandy area.

The only quirk with the S9 is the shortened run time, especially in the max setting at 45 minutes.

Edge Cleaning Comparison

The S9’s square front also gives it a considerable advantage over the J7 in edge cleaning, where it’s more efficient.

Roomba S9 edge cleaning

After the first pass, it picked up most of the debris, and it’s not close.

Here’s a before and after shot of the J7’s edge cleaning experiment.

Roomba J7 edge cleaning

I’d consider the J7 result decent, but it took more than two passes to achieve this result.

The J7’s round frame hampers its efficiency severely.

Hair Wrap Comparison

Furthermore, the S9 is better at picking up hair.

Roomba S9
Roomba J7+
5-inch strands
7-inch strands

Again, thanks to the high airflow, it was more consistent, picking up 81% and 82% with five and seven-inch strands, respectively.

Roomba S9 seven-inch hair wrap

The J7 was decent with five-inch hair but struggled with long seven-inch strands (30% only).

Roomba J7 5-inch hair wrap on axle

You can see in the photo above that most hair strands are wrapped on the axles, which isn’t a bad thing since it’s easier to clean.

Which is Better on Carpet?

Again, the S9 is the better option on carpet. It picked up more with surface and embedded dirt than the J7.

Its high airflow, wide extractors, and side brush placement give it a huge advantage over the J7.

The S9 is the best (by far) in the deep cleaning test with its 93% pick up (versus the J7’s 85%).

I’ll repeat it. The S9 is a better option for carpets.

Run Time Comparison

While the S9 is the better vacuuming robot, the J7 will run longer.

It’s not because it has a larger battery, but because it has a smaller motor and will run for 85 minutes.

This figure is slightly higher than the I6 and I3’s number of 75 minutes.

If there’s one downside to the S9’s monster airflow, it’s the short run time, considering its premium price tag (only 75 minutes).

The S9 utilizes iRobot’s largest capacity battery: 3600 mAh, but the high-powered motor uses up a huge chunk.

Compared to other brands like Roborock (180 minutes), the S9’s run time is short.

Noise Comparison

Power setting
Roomba J7
Power setting
Roomba S9+
63 dB
66.3 dB
68.5 dB
74.1 dB

The good news for J7 potential buyers is that it won’t be as noisy as the S9. I used a sound meter to check noise levels, and it only registered 63-decibels.

In comparison, the S9 can get annoyingly loud, maxing at 74.1 decibels.

The J7’s lower power output is a primary reason it isn’t as loud, but the clean base station will be screaming when it engages (over 84 decibels).


These Roomba products will require some TLC to function at their peak. 

I’ll enumerate which components to replace or clean at specific intervals below.

  1. Extractors: These rollers take the most abuse and need frequent cleaning. Once a week, take these out and wipe using a slightly damp microfiber towel to remove debris accumulation. Check the axles for any hair wrapping on them to eliminate unnecessary friction.
  2. Side brush: Check once a week for hair tangling on the prongs or the base. Remove the side brush and clean accordingly.
  3. Dustbin and filter: Empty the dustbin after every run (automatically done for you if you purchase the “plus” variant). Check the dustbin once a month and clean any accumulation. Also, examine the filter and clean dirt sticking on the folds (tap it on a solid surface to dislodge).
  4. Robot body: Wipe the robot frame to rid it of fingerprints and dust.
  5. Drop sensors: Use a clean microfiber towel or any cotton bud to clean the drop sensors. These are found underneath the robot. Please check these Roomba maintenance articles for detailed steps.
  6. Clean base station: Empty the bag when it reaches full capacity. The iRobot app will notify users when this happens. Check the port on the ramp for any blockages that may hamper the clean base’s vacuum function.

Availability of Parts

Roomba products historically have excellent parts availability. Consumers won’t have any issues purchasing easy-to-find parts such as the battery, side brush, extractors, etc.

The beauty of iRobot products is even hard-to-find components like the bumper sensor, brush assembly, side brush motor, caster wheel are abundant in online stores like eBay and Amazon.

One reason is iRobot’s popularity, so both score high marks here.

Product Specifications

Roomba S9+
Roomba J7+
Roomba S9+
Roomba J7+
13.34 "
Smart Navigation
Smart Navigation
Run time
75 mins.
85 mins.
Recharge and Resume
Map Saving
Number of Maps
Dustbin capacity
500 ml
400 ml
Auto empty capacity
25 CFM (Max)
7.27 CFM
1-year limited
1-year limited

Where can I buy these robots?

The Roomba J7 and S9 are available in online stores like Amazon. Check the links below for the latest pricing information.

  • Roomba J7+ on Amazon (with clean base station)
  • Roomba J7 on Amazon (no clean base station)
  • Roomba S9+ on Amazon (with clean base station)

Disclaimer: I will earn a commission if you purchase through any of the links above, but at no extra cost to you, so it’s a win-win for us!

Which is the Better Option, the Roomba J7+ or S9+?

Two robots, different price tags, varying features, which is better?

The answer depends on what you prioritize and how much you’re willing to spend.

While the S9+ is the better performing robot (in terms of cleaning), the J7 is cheaper, less noisy, and avoids obstacles better.

It all boils down to what you want, and I’ll enumerate why you should opt for a specific variant.

4 Reasons to Choose the Roomba S9+

  1. Superior cleaning performance: The Roomba S9 is a much better cleaning robot than the J7 at surface and embedded dirt.
  2. More efficient: Its wide extractors and high airflow will pick up more debris per pass.
  3. Misses fewer spots: The broad cleaning path ensures it misses fewer spots and will clean edges better.
  4. Deep cleans carpet better: Another benefit of the high airflow is its deep cleaning performance, the best by far among robot vacuums I’ve tested.

4 Reasons to Choose the Roomba J7+

  1. Cheaper option: The Roomba J7 will cost less than the J7 and is much cheaper on the right season (e.g., sale season).
  2. Avoids obstacles better: The front-facing camera and LED will evade objects like pet feces and stretched-out wires. Plus, the algorithm is smart enough not to let the robot get too close.
  3. Still decent performance: The J7 is still decent with cleaning debris, especially on carpet, even with the low airflow.
  4. Stores an extra bag: Users can store an extra bag in the J7 clean base station.

The Verdict: Choosing One Will Depend on Your Needs

These two robots bring something unique to the table.

The Roomba S9, with its square front brings best-in-class cleaning performance and vacuuming efficiency thanks to its broad extractors and high airflow.

In comparison, the J7’s front-facing camera will avoid obstacles better than any robot vacuum.

Its algorithm is intelligent enough not to get too close and a viable option for pet owners who may not clean pet feces on the spot.

This variant is the first robot I’ve tested capable of avoiding large and small pet stools.

Plus, it has a Pet Owner Official Promise (or POOP), where iRobot will replace it for free if it touches dry pet feces. Are you taking the challenge?

About the author: Garrick, the visionary behind Cordless Vacuum Guide, brings over a decade of hands-on expertise in cordless vacuum testing to his insightful reviews showcased on this platform. Beyond his passion for empowering consumers with informed choices, he cherishes precious moments with his family, exploring global cuisines and exploring different horizons with his beloved wife and son. Follow him on Youtube, Tiktok, Facebook, and Instagram.