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Roomba from iRobot has been in the robotic vacuum game for a few decades now, which means they have enough experience that all of their products are top line contenders. Although this is a positive, it can make the task of choosing a Roomba seem almost impossible. While the s9 and i7 Roomba models have many similarities, they have enough differences that when laid out and compared, making a decision between the two, will be a lot easier. You will see it in this Roomba s9 vs i7 features comparison.

Differences Between Roomba i7 vs s9

the i7

the s9


With the classic round, puck-like shape, the Roomba i7’s design appears almost identical to previous Roomba models. Though the Roomba i7 brought many improvements, they certainly don’t shine through in the design, since the Roomba i7 keeps the classic charcoal and gray color scheme, and glossy finish of previous models.

It has a diameter of 13.31” across and a height of 3.62”, which is technically a bit smaller than the previous i6 model, though this difference is virtually indistinguishable. This Roomba appears rather minimalist, with only three buttons; home, clean, and spot clean, which aren’t even completely necessary since the Roomba i7 can be controlled through the iRobot home app or voice commands.

While the Roomba i7 kept many classic Roomba design elements and could be easily mistaken as an earlier model, the Roomba s9 on the other hand, definitely stands out from the rest. The main design element that makes the Roomba s9 stand out against the many past decades of Roombas, is the shape. With the s9, Roomba went with a slick looking, D-shape, so essentially a puck with one straight edge cleaning. This means that the Roomba s9 will be able to reach those corners that the circular Roombas could never access.

Another new improvement in the s9’s design, is the matte finish, which not only looks expensive, but will also do a better job of resisting dirt and fingerprints that can accumulate quite quickly on a glossy surface. With a diameter of 12.3” and a height of 3 5 inches”, the Roomba s9 is slightly smaller than the i7, as well as previous Roomba models.

While the other design alterations were made as improvements in how the Roomba functioned, the addition of the gold, record-looking plate on the s9’s top, is mostly for aesthetic purposes. That being said, the sleek gold plate does actually cover robot Roomba s9’s large dirt cup, and looks good while doing it.


For Roomba S9 vs Roomba i7, they weigh 7.44 pounds and 8.2 pounds respectively. Although the Roomba s9 is technically heavier than the Roomba i7, the difference in weight is almost unnoticeable, unless you would be carrying the machine for a long period of time. For the irobot roomba s9 vs irobot roomba i7, both are quite light, and at just around 8 pounds the weight is similar to that of a fully-grown cat or a newborn-baby. The weight is pretty much on par with the previous models (if not slightly heavier,) which have all weighed under 10 pounds.

Interface and Controls

As mentioned above, the Roomba i7’s interface is quite simple, with only 3 buttons in the center; home, clean, and spot clean, on the machine. While the buttons on the i7 can be helpful, they truly are no longer necessary, since the Roomba can be controlled by the iRobot home app or voice commands. Through the app and voice commands you will actually have more control, since on top of the same controls the buttons offer, you can schedule cleanings and send the Roomba robot to clean specific rooms.

Although the Irobot Roomba s9 has the same three buttons as the Roomba i7, the upgraded design has relocated those controls from the middle to the upper right of the Roomba robot. The interface is identical to the i7’s, since you can control the s9 through the buttons, app or voice commands.


Both the irobot Roomba s9 and irobot roomba i7 have a lithium ion battery which takes around 2 hours to recharge from empty to full. That being said about lithium ion, the Roomba i7’s run time is 90 minutes (an hour and a half,) while a fully charged Roomba s9 battery ensures 120 minutes (two hours) of clean time. Although the i7’s battery life is shorter than the s9 and cannot reach 120 minutes or lower than 120 minutes, there is no need to worry about it not finishing the job since both the Roomba i7 and Roomba s9 have the Recharge and Resume features. This means that in this Roomba i7 vs s9 comparison, both models will return to their dock when the battery is running out, and once fully charged they will pick up cleaning where they left off.

What this essentially means is that if you plan to set your Roomba robot to clean while you are at work, both models will likely be able to finish cleaning before you return. While the s9 is a clear winner in battery life, providing an extra 30 minutes of cleaning (without any extra charge time) it is important to consider whether the extra cleaning time is really necessary.

If you have a larger home that will take a longer time to clean, or if you use the Roomba robot while you are home or before hosting people, the s9’s extra 30 minutes of cleaning time may be necessary. On the other hand, as mentioned before, if you schedule your Roomba to clean while you are out for the day and you have an average sized home, the extra 30 minutes will likely make no difference to you.

Clean Base Charging Station

Both the Roomba s9 and i7 offer a “plus” option which come at a higher price, but include the clean base charging station. These features were actually first introduced into commercial robot vacuums with the Roomba i7 model, but considering how useful it is, we expect it to be a regular features for all robot vacuums in the future. The clean base charging is essentially a step up from the regular charging station, which the Roomba will automatically return to when it is in need of a battery charge.

Now on top of automatically recharging, with the “plus” models, the Roombas will automatically empty the dust bin. What this means is there is literally no more need to touch the Roomba at all, except for occasional checks. These features are perfect and almost necessary for those who have bigger homes, who intend to use their robot Roomba when they are not home. Overall, the clean base charging system, which is made to contain around 30 dust cups of dirt, takes the last little bit of hassle or chore left in using a robot vacuum.  Since you will likely only have to empty out the clean base around once a month or so.

Dust Cup Capacity

Similar to the weight of the robot vacuums, while there is a difference in the dust cup capacity for Roomba i7 vs s9, the difference is so slight that it really only makes a difference in certain situations. The Roomba s9’s dust cup has a capacity of 0.4 liters, while the i7 can contain 0.3 liters. Since 0.3 liters is generally more than enough to clean a floor in an average sized home, the difference in dust cap capacity really should only impact your decision if you have a larger sized home, or cannot empty the dust cup very often. This difference becomes almost completely unimportant if you choose to upgrade to the “plus” option, which offers the clean base charging system which will automatically empty the dirt cap for you, every time the Roomba docks.


Both the s9 and i7 Roombas come with the same high-efficiency filter which is supposed to trap 99% of allergens, dirt, and mold. While the filter provided in Roomba i7 vs s9 both robot vacuums is top of the line and extremely efficient, it is a step below HEPA filters which trap 99.99% of allergens. This 0.99% difference is virtually indistinguishable to all those without allergies, so if you and your family are not extremely sensitive to allergens the filter provided in the Roombas will do fine.

That being said, anyone who suffers from allergies, would likely agree that that 0.99% can make a huge difference and that the high-efficiency filter in the s9 and i7 models may not be strong enough. If this is the case, do not worry, since Roomba’s i7 and s9 models are compatible with third party HEPA filters.

Noise Levels

If you have ever owned a robot vacuum or been in a home of someone who owns one, you will know Roombas are extremely quiet, especially when compared to regular traditional vacuums. The s9 and i7 have noise levels of 64 and 62 decibels respectively, which is quite a lot lower than the average vacuum cleaner which has a noise level of around 75 decibels. Though the s9 is louder than the i7, this 2 decibel difference would be almost impossible to notice. Overall, both the i7 and Roomba s9 Roombas have about the same noise levels, which are quite low and have about the same noise level as a normal conversation would.

S9 and I7 Navigation

Both the Roomba s9 and i7 share iRobots advanced navigation and imprint smart mapping yes system which are camera-based and features “Imprint Smart Mapping Technology.” When you first bring home your roomba (as well as occasionally in the future,) it will move around the house without the motor on and without actually vacuuming.

These “training runs” as Roomba calls them, allow your robot vacuum to learn the layout of your home and create a map, so it can clean in the most efficient way possible. Since the “Imprint Smart Mapping Technology” allows your robot roomba to save the layout of your home, you will also be able to use voice commands or the app to send your robot vacuum to clean a specific room in your home.

Roomba S9 and I7 Suction Power

While there is no exact way to measure suction power, tests can be done with an anemometer to compare the suction power of the roomba s9 and i7. Comparing the i7 and s9 is strange not only because of the potential margin of error in the tests, but also since they have different not exactly comparable power modes. The s9 has a high and low power mode, whie the i7 has one singular power mode that adjusts based off of the surface you are cleaning. To try and make the tests accurate, the i7 was used on a carpet since that is when a vacuum’s suction needs to be it’s strongest.

The results of the anemometer found the s9 on low to produce 8 CFM of airflow and while on high it produced 22 CFM of airflow. Of course since the i7’s suction shifts automatically, the results shifted, but the highest it went up to was around 17 CFM and the lowest was around 7 CFM. Taking into account the margin of error and the inaccuracy of the i7’s automatic shifting airflow, this difference in suction is still quite substantial. While these numbers may not be exact, they do show that the s9’s suction power is quite a deal higher than that of the i7’s, therefore, making it high efficiency and thorough.

According to Roomba, the i7 has stronger suction than around 70% of commercially available robot vacuums on the market. They also claim that the s9 is around four times more powerful than the i7. Essentially what this means is that the i7 is extremely powerful, definitely more than powerful enough for a home with hardwood floors.

However, the s9 goes above and beyond, with a suction power that is in the same league as high level robot vacuum, appropriate even for a home that is mostly carpeted.

Brushes and Cleaning Capabilities

The Roomba i7 model maintains the brush layout and ability of early Roomba models. Inside the i7 there are two rubber brush, which work together to prevent hair, fur and debris from getting caught in the machine, while also efficiently cleaning the floors. These brushes have three prongs which keep them spinning side at quite a fast pace, which is efficient but also flawed since the heightened speed means that debris can fling out of the machine. The i7 tends to work extremely well on hardwood floors, but struggles on carpets and of course with corners, since the rounded shape makes it difficult to get access.

Much like the i7, the s9 has Roombas patented dual rubber brush, however, that is about where the similarities end. As mentioned in the design category, the s9 is shaped like a “d” which means it has a straight edge. This straight edge cleaning not only means that the s9 is capable of accessing corners, it also means that the brushes are extended along the straight edge clean. The s9’s square front features wider extractors which are in fact 30% wider than previous side brushes, making them not only more efficient but also more thorough.

These extended side brushes have more prongs than that of the i7’s, which means that the s9’s brushes move quite a bit slower. While this may sound like a disadvantage, it is in fact quite a big positive the slower speed prevents any debris from flinging out of the robot vacuum. Since the s9 has more thorough brushes as well as a stronger suction power, it performs well on all floor types including carpets (even high pile carpet.)

Hardwood Cleaning 

The Roomba i7 works best on hardwood cleaning, and certainly best surpasses previous model in cleaning capabilities. Although the i7 is quite powerful, more powerful than around 70% of other robot vacuums, it certainly isn’t perfect specifically with hair and sand. While the i7 does well picking up short pet hair, it struggles picking up human hair, and even with the dual rubber side brush system, longer hairs can get caught in the extractors.

The i7 was perfectly capable at picking up all fine debris except for sand, which as mentioned above, the accelerated side brush speed can potentially fling sand around instead of sucking it up. Overall, the i7 does an excellent job vacuuming up all debris and dirt on hardwood, but it struggles a bit with sand and long hair cleaning.

The s9 performs quite similarly to the i7 Roomba vacuum, and does exceptionally well on hardwood floors. Much like the i7 robot vacuum, the s9 tends to struggle a bit with long human hairs, which can potentially get caught in the brushes and extractors. Where the s9 differs from the i7 is its capabilities for cleaning sand and of course cleaning corners. The s9 robot better than the i7 but not only has stronger suction than the i7, but it also has a slower side brush speed which means there is no chance for sand to be flung around.

Other than with sand, the only other real noticeable difference between s9 and the i7 cleaning on hardwood, is that the s9’s straight edge allows it to get into tight corners and clean right along the corners and edges of walls, providing a more thorough overall clean in those hard to reach areas. Unless you live near a beach, the difference between the i7 and s9’s cleaning capabilities will go virtually unnoticed (other than in some harder to reach corners where the circular i7 can’t use suction.)

Carpet Cleaning 

While the i7 robot vacuum is perfectly capable of cleaning carpets and rugs, this is the category where the s9 really shines. With the stronger suction power, the s9 is capable of getting deep into even the hardest to clean carpets (such as high pile rugs, or extremely thick shaggy carpets.) As mentioned above, the i7 only has one power option where it automatically adjusts to the surface it is cleaning.

The s9 on the other hand has a specific high-power control that is meant for cleaning carpets, which require far more suction than hardwood floors. Overall, the s9 will be far more efficient at vacuuming carpets, and if your home is mostly carpeted it would definitely be worth investing in an s9 over the i7. That being said, if you only have low-piled, small-haired rugs or just one carpet, you will probably be fine with an i7.

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The main, routine maintenance necessary with a Roomba, is emptying out the dirt cup. Generally you will want to empty it out after every use, if possible, since when the dustbin fills up, the roomba won’t be able to clean base anymore. To make matters easier, you can actually receive a notification on your app to let you know when the dust bin needs to be emptied, however, it may be inconvenient if you are out of the house. Generally, the s9 and i7 provide enough capacity for a single clean, but if you have a larger home, you may need to empty out the dirt canister more often.

If you want to almost completely cut out maintenance for your roomba, you can upgrade to the “plus” models, which include a clean base charging system, or in other words, the ability to automatically self-emptying at the dock when the dirt cup is full. The base “dump” is capable of holding up to 30 dustbins of debris, meaning you can likely go a whole month without emptying the dock’s dustbin.

While the self-emptying “plus” edition roombas take almost all of the maintenance out of your roomba, there is still some work that is required every so often. On top of occasionally emptying out the dock’s dustbin, you will want to routinely replace the filter. While most people do not do this, it is actually recommended that you change your roomba’s filters every month or two. Though it may seem excessive, the efficiency of the robot vacuum severely decreases with an old filter, which can make a huge difference (especially to those with allergies,) in the cleanliness of your home.

If you ever feel as if your roomba is working a bit slower or less efficiently than usual, it is probably a good idea to check the side brush, side extractors and wheels. As detailed above, it is actually quite common for long pet hair to get caught up in these parts. Even if your roomba is working normally, it is a good idea to routinely check the side brush, side extractors and wheels to ensure there is no excessive wear or tangles that could potentially cause a future problem.

A simple, yet necessary part of maintenance with both the Roomba s9 and i7 is cleaning the sensors and camera. Roombas have sensors and a camera, which allow the robot vacuum to navigate around the house, find its way back to the dock and indicate to the app when the dustbin is full. To ensure that the sensors and camera are able to perform all of these tasks, it is important to give them a wipe down to remove any dirt, once every two weeks or so.

Factors To Consider

If you are having trouble deciding between the Roomba s9 and i7, considering the following factors should help you make a choice as to the model that will work the best for your situation.

1. Price

The price difference between the s9 and i7 is quite substantial, and although the price fluctuates, the i7 can usually be found for hundreds of dollars less than the s9. Another potential price addition would come from upgrading to the “plus” models. The i7+ and s9+ vacuums function exactly the same as the regular i7 and s9’s do, however, the “plus” comes with the clean base charging system, which essentially makes the roomba’s self-cleaning.

The “plus” model will save you time, since you will only have to empty the dustbin around once a month (rather than every day or so) and it will allow the machine to keep running without any disturbances due to a full dust canister. When considering price, it is extremely important on top of budget, to consider what are your necessities. If you will be using the roomba when you are home, you technically don’t need the “plus” self-emptying features, although it would be useful. No matter what, a high-quality vacuum of any kind is an investment, and if you are investing in a robot vacuum it should make your life easier, not harder so consider your situation and which vacuum works better for your needs.

2. Flooring

As mentioned above, both the s9 roomba i7 performs extremely well on hardwood flooring. Though the i7 struggles a bit with sand, unless you live near a beach, it functions just as well as the s9 on hardwood. Where the real difference lies between the s9 and i7 models, is in their cleaning capabilities with carpets. The s9 model has a far stronger suction power than the i7, making it better suited to carpets. Though the i7 Roomba does quite well on low-pile rugs, it cannot keep up with the s9’s capabilities on shag and high-pile carpets. If your home is mostly carpeted, especially with high-pile rugs, it will definitely be worth it to invest in the s9 Roomba.

3. Additional Cleaning

The d-shape of the s9 allows it to clean base right up against the walls and access even the hardest to reach corners. The i7’s circular design on the other hand, tends to struggle in these areas. Though the i7’s suction is capable of picking up most of the serious debris in corners and along edges, there may be some additional cleaning performance necessary every so often.


With so many tic vacuums on the market, it can seem impossible to make a decision. Since the Roomba s9 and i7 are both excellent, recent robot vacuums, made by the same company, they share many similarities which can make the decision process even more difficult. Overall, the Roomba i7 is a far more budget conscious option that provides a thorough clean base on hardwood and low-pile rugs.

That being said, the Roomba s9 has a stronger suction power than the i7 and a d-shaped design, which allows it to get into hard to reach corners and provide a more thorough clean base on high-pile carpets. Although both are excellent options, with all of the information laid out, the real deciding factors come down to your flooring, budget and additional cleaning intentions, and once you take into account your personal necessities, making a decision between the two will feel much more possible.

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