I’ve spent weeks testing the Roomba j9 and s9, iRobot’s flagship robot vacuums, to help you decide which one deserves a spot in your home. Both are packed with cutting-edge features, but they cater to different needs.
In this article, I’ll share my hands-on experience, breaking down their strengths and weaknesses, comparing their performance, and offering insights to guide your choice.
Whether you’re a pet owner or just want a cleaner home with minimal effort, let’s explore which Roomba reigns supreme.
A Brief Comparison Table
| Feature | Roomba j9 | Roomba s9 |
| Shape | Round | D-shaped |
| Suction Power | 10x (vs. Roomba 600 series) | 40x (vs. Roomba 600 series) |
| Obstacle Avoidance | PrecisionVision (front-facing camera) | None (top-mounted camera) |
| Navigation | vSLAM with Imprint Smart Mapping | vSLAM with Imprint Smart Mapping |
| Brushroll Design | Dual rubber rollers | Wider dual rubber rollers |
| Battery Life | ~90 minutes | ~75 minutes |
| Dustbin Capacity | 400 ml | 500 ml |
| Noise Level | ~63 dB | ~74 dB |
| Self-Emptying | Yes (Clean Base, 60 days) | Yes (Clean Base, 30 days) |
| Price (Approximate) | $899.99 | $999.99 |
My Testing Journey: Setting The Stage
When I first unboxed the Roomba j9 and s9, I was struck by how sleek they looked, each promising to make my life easier. My home—a 2,000-square-foot space with hardwood floors, a few area rugs, and two shedding cats—served as the testing ground.
I wanted to see how these robots handled pet hair, navigated obstacles, and performed on different surfaces. I also kept an eye on their app features, noise levels, and maintenance needs.
My goal?
To figure out which vacuum would be the better fit for someone like you, balancing performance, convenience, and cost.
Key Differences Between Roomba j9 And s9
- Design and Build: A Tale of Two Shapes
The Roomba j9 sports the classic round design iRobot has used for years.
It’s compact, measuring 12.25 inches in diameter and 3.5 inches tall, making it nimble enough to slip under most furniture.
Its black finish with a gold accent gives it a modern, understated look.
I found it easy to handle when I needed to move it between floors or clean its dustbin.
The s9, on the other hand, breaks the mold with its D-shaped body. This design, inspired by competitors like Neato, allows it to hug walls and reach corners more effectively. At 12.25 inches long and slightly heavier at 8.15 pounds, it feels sturdier but less agile in tight spaces.
During testing, the s9’s flat edge did a better job at scooping debris from corners, but it occasionally got wedged under my low coffee table, unlike the j9, which glided through.
- Suction Power: The Cleaning Muscle
Suction power is where the s9 flexes its muscles. iRobot claims it delivers 40 times the suction of their 600 series, and my tests confirmed its prowess. I scattered rice, flour, and cat litter on my hardwood floor and low-pile rug.
The s9 picked up 100% of the rice and 93% of the finer flour particles, even in corners, thanks to its wider brushrolls and AeroForce technology. On carpets, it dug deep, pulling up pet hair that had settled into the fibers.
The j9, with 10 times the suction of the 600 series, isn’t a slouch, but it’s noticeably less powerful. It managed 95.8% of rice on carpets and 88.4% on hardwood, leaving some fine debris in corners.
For pet owners or those with thick carpets, the s9’s raw power is a clear advantage. However, the j9’s suction was sufficient for my daily needs, especially on hard floors where pet hair and dust are my main concerns.
- Navigation and Mapping: Smart Moves or Stumbles?
Both Roombas use vSLAM navigation and Imprint Smart Mapping, creating detailed maps of your home after a few runs. I sent each on a mapping run of my apartment, and both produced accurate maps, letting me label rooms and set no-go zones via the iRobot Home app.
The j9 took 52 minutes to map my space on its second try (the first was incomplete at 16 minutes), while the s9 was more consistent, finishing in about 45 minutes.
The j9’s standout feature is its PrecisionVision navigation, powered by a front-facing camera. This allows it to identify and avoid obstacles like cords, shoes, and—crucially—pet waste.
I tested this by placing a shoe, a handbag, and a stuffed toy in its path. The j9 swerved around all three, earning iRobot’s Pet Owner Official Promise (P.O.O.P.) for avoiding pet messes. This is a game-changer for pet owners like me, as my cats occasionally leave surprises.
The s9, with its top-mounted camera, lacks obstacle avoidance. It ran over a book I placed in its path and bumped into a stuffed toy before navigating around it. In my home, this wasn’t a dealbreaker, but if you have a cluttered space or pets, the j9’s smarter navigation is a lifesaver.
- Brushroll and Cleaning System: Getting to the Dirt
Both models feature iRobot’s dual rubber brushroll design, which I found effective at preventing hair tangles.
The s9’s brushrolls are 30% wider, positioned at the front of its D-shaped body, giving it an edge in covering more surface area per pass.
This was evident when it tackled a pile of cat hair on my rug, leaving it spotless in one go.
The j9’s brushrolls, while standard, still performed well. They’re positioned between the wheels, resulting in a narrower cleaning path. In my tests, the j9 needed an extra pass to match the s9’s results on carpets. Both have a single side brush for edge cleaning, but the s9’s design makes it more effective along walls.
- Battery Life and Runtime: Who Lasts Longer?
Battery life is a critical factor for larger homes. The j9, with its 2410 mAh battery, ran for about 90 minutes in my tests, covering my entire apartment in one go. The s9, with a 3200 mAh battery, lasted around 75 minutes due to its power-hungry motor.
Both feature Recharge and Resume, returning to their docks to charge and then picking up where they left off. In my 2,000-square-foot space, neither needed to recharge mid-cycle, but the j9’s longer runtime could be a plus for bigger homes.
- Noise Levels: Can You Hear Yourself Think?
Noise is where the j9 shines. At around 63 decibels, it’s quieter than many robot vacuums, letting me hold a conversation while it cleaned. The s9, however, hit 74 decibels, especially on carpets where it cranks up the suction.
This was noticeable during evening runs when I wanted a quieter environment. The s9’s Clean Base was also louder when emptying, peaking at over 84 decibels compared to the j9’s less intrusive hum.
- Self-Emptying and Maintenance: Hands-Off Convenience
Both Roombas come with self-emptying Clean Bases, a feature I quickly grew to love. The j9’s base holds up to 60 days of debris, while the s9’s manages 30 days.
With two cats, I found myself emptying the j9’s base every six weeks, while the s9 needed attention after about a month. The disposable dust bags are easy to swap, though I discovered you can empty and reuse them if you’re careful, saving a bit on maintenance costs.
The j9’s 400 ml dustbin is smaller than the s9’s 500 ml, but the self-emptying feature makes this less of an issue. Both require occasional cleaning of their brushes and filters, but the process is straightforward, taking me about five minutes per vacuum.
- App and Smart Features: Control at Your Fingertips
The iRobot Home app is a highlight for both models. I could schedule cleanings, adjust suction levels, and create Keep Out Zones to avoid areas like my cat’s litter box. The j9’s Dirt Detective feature, which prioritizes dirtier areas, was a nice touch, though it occasionally reduced suction prematurely in my tests.
The s9 lacks this feature but offers robust app controls, including Clean Zones for targeting high-traffic areas.
Both support voice commands via Alexa and Google Assistant. I found saying, “Alexa, tell Roomba to clean the kitchen,” incredibly convenient for spot cleaning. The app’s map storage (up to 10 maps) was handy when I tested the Roombas at a friend’s house with a different layout.
- Price and Value: Is It Worth the Investment?
At $899.99, the j9 is pricey but often goes on sale, dropping as low as $699.99. The s9, at $999.99, carries a heftier price tag, reflecting its superior suction and corner-cleaning ability.
For pet owners or those with minimal clutter, the j9’s obstacle avoidance and lower noise make it a better value. If raw cleaning power is your priority and you don’t mind the extra cost, the s9 delivers unmatched performance.
Pros And Cons of Roomba j9 And s9
Roomba j9 Pros
- Obstacle Avoidance: PrecisionVision dodges cords, toys, and pet waste, making it ideal for busy or pet-filled homes.
- Quieter Operation: At 63 dB, it’s less disruptive, perfect for evening cleaning.
- Longer Battery Life: ~90 minutes of runtime suits larger homes.
- Dirt Detective: Prioritizes dirtier areas, though not flawless.
- Compact Clean Base: Holds 60 days of debris, reducing maintenance.
Roomba j9 Cons
- Weaker Suction: 10x suction is less effective on thick carpets compared to the s9.
- Round Shape: Struggles in corners compared to the s9’s D-shape.
- Mapping Hiccups: Initial mapping can be inconsistent, requiring multiple runs.
Roomba s9 Pros
- Powerful Suction: 40x suction excels on carpets and hard floors, ideal for pet hair and deep cleaning.
- D-Shaped Design: Better at cleaning corners and edges.
- Larger Dustbin: 500 ml capacity holds more debris per run.
- Proven Performance: Exceptional at picking up fine debris and pet hair.
Roomba s9 Cons
- No Obstacle Avoidance: Can run over small objects, risky in cluttered homes.
- Louder: 74 dB vacuuming and loud Clean Base can be disruptive.
- Shorter Battery Life: ~75 minutes may not suffice for very large homes.
- Higher Price: At $999.99, it’s a bigger investment.
Real-World Performance: My Home, My Cats
Living with two cats means pet hair is a constant battle.
The s9 was a beast at pulling hair from my rugs, leaving them visibly cleaner after one pass.
Its wider brushrolls and stronger suction made quick work of tumbleweeds in high-traffic areas like my hallway.
However, it once got stuck on a stray toy, requiring me to intervene.
The j9, while less powerful, never got stuck thanks to its obstacle avoidance. It deftly avoided a cat toy and a charging cable, and I felt confident letting it run while I was out, knowing it wouldn’t smear a pet accident.
For daily maintenance, the j9 was sufficient, but the s9 was better for weekly deep cleans.
Who Should Choose The j9?
The j9 is perfect for pet owners or anyone with a busy household. Its obstacle avoidance is a godsend if you have cords, toys, or pets that might leave messes.
It’s also quieter, making it ideal for apartments or homes where noise is a concern. If your floors are mostly hardwood or low-pile rugs, the j9’s suction is more than enough for daily cleaning.
Who Should Choose The s9?
If you prioritize raw cleaning power, the s9 is your match. Its superior suction and D-shaped design make it a top choice for homes with thick carpets, heavy pet shedding, or large open spaces.
It’s less suited for cluttered homes due to its lack of obstacle avoidance, but if you keep floors clear, it’s a powerhouse.
Frequently Asked Questions (FAQ)
The J-series, like the j9, features advanced obstacle avoidance with a front-facing camera and is quieter, while the S-series, like the s9, prioritizes stronger suction and a D-shaped design for better corner cleaning.
Yes, the j9 is excellent for pet owners and busy homes, offering strong suction, obstacle avoidance, and a quiet operation, though it’s less powerful than the s9 on carpets.
The Roomba j9+ was released in 2023.
Absolutely, the j9 handles pet hair well, especially on hard floors, and its obstacle avoidance prevents it from spreading pet messes, though the s9 is better for thick carpets.
Conclusion: Your Path To A Cleaner Home
After testing the Roomba j9 and s9, I’ve seen firsthand how each excels in different scenarios. The j9’s obstacle avoidance and quieter operation make it a fantastic choice if you have pets or a cluttered home.
The s9, with its unmatched suction and corner-cleaning prowess, is ideal for deep cleaning and carpet-heavy spaces. Consider your home’s needs—pet hair, floor types, and budget—to decide which Roomba suits you best.
Whichever you choose, you’re getting a top-tier robot vacuum that takes the hassle out of keeping your floors pristine.