Roborock S4 Max Review

Roborock S4 Max Review

The S4 was one of the more popular Roborock options because of its lower than premium cost and high-end performance.

It now gets a refresh with the S4 Max. Roborock says this model gets a bump in power at the max setting with better climb-ability over thresholds, particularly carpets and rugs.

One of My Favorite Roborock Products to Date
  • Navigation - 97%
  • Surface Cleaning - 99.2%
  • Deep Cleaning - 80.2%
  • Quality - 95%
  • Design - 96%
  • Value - 98%


Like the Roborock S4, the S4 Max offers consumers a more cost-effective option. This model has the same features as the more expensive S5 Max minus the mop. So you’re essentially getting an S5 Max for much less. It also doesn’t clean embedded dirt, but the difference isn’t much. One reason why the S4 is popular is the lower-than-usual cost. The S4 Max provides the same high-end features, lower cost-benefit as the S4, and more airflow.


  • Strong airflow at over 20 CFM
  • Great at picking up surface dirt
  • One of the least expensive, efficient and smart navigation with invisible walls and no-go zones
  • All-rubber side brush has better durability
  • Decent at deep cleaning with an 80.2% average


  • Only average at cleaning edges
  • Smallish dust bin
User Review
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Introduction to the Roborock S4 Max

The S4 Max is perhaps the best value-for-money option in the Roborock product line. You’ll get high-end features without having to pay the premium cost.

Roborock lowered the price because this model doesn’t have an electronic water tank.

It’s an upgrade over the S4 (discontinued) with some cosmetic and performance upgrades. First, we’ll look at the aesthetic changes. Gone is the glossy black finish.

The S4 Max now has a matte black finish, which I like since it’ll age better. What I mean is it won’t be a finger-and-scratch magnet. The layout is also different as the S4 Max integrates facets of the S5 Max into its design.

Roborock S4 Max

It’s basically an S5 Max with a matte finish with the same button placement (above the LIDAR).

The Roborock rep I talked to says the S4 Max has more suction at the max setting. Another enhancement is the improved climb ability over thresholds (emphasis on rugs and carpets).

Underneath, the layout remains the same with a single side brush and combo brush.

Roborock S4 Max underneath

All the latest Roborock options utilize the all-rubber side brush. I prefer this to the older version with the bristled tips for longevity.

Dustbin capacity

The Roborock S4 Max has a top-mounted dustbin with a 0.46-liter capacity.

Roborock S4 Max dustbin placement

It’s not huge, but decent for daily clean-ups. Behind it is a washable HEPA filter. This container has a front door to dispose of dirt.

Roborock S4 Max dustbin open

The opening is decent, and there shouldn’t be any issues emptying the contents. Make sure to have a wide enough trash container for it.

How does the Roborock S4 Max navigate?

Like all Roborock options, the S4 Max relies on a LIDAR sensor to track and map out its location. I like a laser sensor because of its precision and non-reliance on light to navigate.

The S4 Max will traverse along the edges before cleaning the middle portions in straight lines.

Users can increase or decrease passes between one and three times. This feature provides a level of flexibility you don’t often see in other brands at this price point.

For instance, the 360 S6 robot doesn’t have this capability. It will go around once by default, and users can only adjust the number of passes in the zone tab.

The only other brand with this feature is the Neato Botvac.

I highlighted this feature because it’s something essential to getting a thorough clean.  Robots that only go around once won’t be as effective as those with multi-pass capabilities.

Roomba products can get away with a single pass run because it has “dirt detect” that does additional passes on dirtier zones.

Invisible wall

Another essential feature the S4 Max has is the invisible wall. This feature enables users to add lines through the app to block the robot from off-limit zones.

Every home has such, and the ability to set lines diagonally provides more options to consumers.

Again, other brands at the S4 Max’s price point don’t have this feature.

No-go zones

Another app feature included in all Roborock S-series robots is the no-go zones. It enables users to set off-limit rectangular or square zones.

No-go zones are useful if you have small areas at home you like to block, like the kitty litter area or perhaps a big rug with tassels.

It’s another wrinkle to an already feature-rich app.

App features

Roborock S4 Max app

The Roborock S4 Max is only compatible with the Roborock app, and I have great news. With the new app rollout, users can now name rooms, something not available previously.

Since this variant doesn’t have a water tank, the mopping tab won’t be present, nor the no-mop zone. But it has the no-go zones, which have a similar function, so it shouldn’t be a deal-breaker.

Let’s quickly go through the app features of the Roborock S4 Max.

Invisible wall and no-go zones

Roborock S4 Max invisible wall and no-go zones

These two are essential features that, in my opinion, all robot vacuums must have. The invisible wall and no-go zones are containment features preventing robots from going into off-limit areas. And every home has these zones.

An invisible wall is a line that blocks the robot from going past it like a wall, hence the term. In comparison, the no-go zone is a rectangular or square “zone” that you draw on the map, blocking the robot from going into it.

You can prevent the robot from entering a pet zone or an area rug with lots of tassels.

Carpet boost

With this feature on, the robot will automatically increase suction if it detects carpet. So you can leave it at a lower setting to maximize run time without manually switching to a higher power setting if it goes on carpet.

Live map

The LIDAR sensor permits the S4 Max to monitor its real-time location. With the initial scan, the laser sensor will fire signals around the room to determine its shape. If you’re running the robot the first time, you’ll see in real-time the status of the run, where the robot is, area size, and more.

Once the run is complete, you can save the map and add more maps if you live in a multi-story home. Make sure to activate the “muti-level” feature to save additional maps.

Multi-level map

Roborock S4 Max map saving

Piggy-backing on the previous section, the S4 Max can save up to 4 map levels. One feature I like is the quick-start guide for creating new maps, making the process more straightforward.

There’s no need to switch maps manually since the app will detect it with the initial scan.


Roborock S4 Max scheduling

Lastly, there’s a scheduling feature for unlimited daily runs. The app also provides enough flexibility to select weekday, weekends, or specific days and choose a corresponding power setting fit for the task.

How much power does the Roborock S4 Max have?

I use an anemometer to measure airflow, and here are the results.

  • Quiet: 11.95 CFM
  • Normal: 15.33 CFM
  • Turbo: 18.87 CFM
  • Max: 22.26 CFM

This robot produces over 22 CFM of airflow in the highest setting, which is premium level with the Roomba S9, hundreds of dollars more expensive.

Unfortunately, the S4 Max doesn’t deep clean as a Roomba (E5 and 980). None of the robot vacuums I’ve tested broke the 90% or at least close to it, with the S5 Max being the closest.

Note: I made a slight error with the airflow computation, multiplying the raw wind speed numbers to 0.024099 instead of 0.026099, hence the lower scores. But I’ve made the corrections above.

Cleaning Performance

I put the S4 Max through a series of tests on different debris types like sand, pet litter, coffee grounds, quinoa, quaker oats, cheerios, and hair.

Here are the scores:

  • Overall: 94.45%
  • Hard floor: 99.7%
  • Carpet (surface): 98%
  • Carpet (deep cleaning): 80.2%
  • Sand on hard floor: 99.9%

Hard floor results

Roborock S4 Max cleaning quaker oats on hard floor

Roborock S4 Max cleaning coffee grounds on hard floor

Roborock S4 Max cleaning quinoa on hard floor

Roborock S4 Max cleaning pet litter on hard floor

  • Quaker oats: 100%
  • Coffee grounds: 100%
  • Quinoa: 99.2%
  • Pet litter: 99.6%

The S4 Max did its best work on hard surfaces, scoring nearly perfectly across the different tests. It didn’t get 100% of quinoa and pet litter because the side brush scattered a small portion of it outside the barrier.

This occurrence shouldn’t be a concern in a real-world scenario since the robot only has to deal with dust and hair.

Sand on hard floor

Roborock S4 Max sand on hard floor result

Sand is one of the toughest to clean on hard floors. To check how the S4 Max deals with it, I scattered 50 grams on a test area.

The high airflow of the S4 Max is evident during this experiment, picking up an average of 99.9% – a touch better than the S5 Max.

It’s one of the best robot vacuums for cleaning sand and a strong consideration for those living in a sandy area.

Hair wrap test

I added a few wrinkles to the hair wrap test. Instead of just showing the brush roll, I weigh the hair inside the dustbin and brush.

There are two tests – the first is the 5-inch test (one gram) and the 7-inch test (one gram).

The high airflow showed itself in these experiments as most of the hair went inside the dust container.

  • Five-inch test: 0.8 grams inside the bin and 0.2 grams on the brush
  • Seven-inch test: 0.8 grams inside the bin and 0.2 grams on the brush

Here’s a photo of the hair inside the bin (left) and the brush (right).

Roborock S4 Max hair inside dustbin and brush

It’s an impressive result, especially the results of the seven-inch test. It shows that the S4 Max is a better option in this price range for cleaning hair.

Edge cleaning

Another experiment I did was the edge cleaning tests, where I scattered coffee grounds on one edge of the room in the max power setting.

Here’s a before and after photo.

Roborock S4 Max edge cleaning

The results were excellent, at least with coffee grounds, as it could pick up most of it after a three-pass run. There was minimal scatter even with the side brush spinning more rapidly, cleaning this area.

Carpet results

Next, we’ll look at how the S4 Max did at cleaning carpet (surface and embedded dirt). I used the same debris set, and it had (mostly) excellent scores.

Low pile

Roborock S4 Max cleaning quaker oats on low pile carpet

Roborock S4 Max cleaning coffee grounds on low pile carpet

Roborock S4 Max cleaning quinoa on low pile carpet

Roborock S4 Max cleaning pet litter on low pile carpet

  • Quaker oats: 99.6%
  • Coffee grounds: 93.6%
  • Quinoa: 100%
  • Pet litter: 98.2%

The S4 Max struggles most with fine coffee grounds despite the high airflow. It’s still a high score for non-Roomba products, but it reveals room for improvement with the brush design.

Mid pile

Roborock S4 Max cleaning quaker oats on mid pile carpet

Roborock S4 Max cleaning coffee grounds on mid pile carpet

Roborock S4 Max cleaning Quinoa on mid pile carpet

Roborock S4 Max cleaning pet litter on mid pile carpet

  • Quaker oats: 100%
  • Coffee grounds: 93.4%
  • Quinoa: 100%
  • Pet litter: 99.2%

The results on mid pile somewhat mirror the results on the low pile carpet. It scored a perfect 100% with the quaker oats and quinoa, but it wasn’t as good cleaning coffee grounds. The score was still very decent, but not as good as the Roomba E5 I tested last week.

Deep cleaning

I’ve done many tests to check how well the S4 Max picks up embedded dirt. For the experiment, I used 100 grams of sand on mid-pile carpet and ran the robot using a three-pass run.

It got an average of 80.2%, a shade lower than the S5 Max. I was hoping for a higher score since the S4 Max has more airflow. It may be the brush design, which I doubt because the S4 Max and S5 Max use a similar brush, but these are the results I got, so I’ll leave it at that for now.

How noisy is the Roborock S4 Max?

Even with the high airflow, Roborock did a superb job at muffling the noise.

  • Quiet: 60.6 dB
  • Normal: 62 dB
  • Turbo: 62.4 dB
  • Max: 64.1 dB

It’s a tad quieter than the Roomba E5 and 675 I tested before this.

How long will the Roborock S4 Max run?

Run time is a strong suit for the S4 Max. It can run for up to 180 minutes in its quiet setting, so it covers a lot of ground. But run time doesn’t matter as much for smart robot vacuums with recharge and resume since it resumes cleaning (automatically) if it doesn’t complete the task previously.

What comes in the box?

You’ll get these items out of the box.

  • Roborock S4 Max robot vacuum
  • Charging base and plug
  • Extra HEPA filter
  • User manual and quick start guide

Availability of Parts

Accessibility to Roborock parts has improved over the years with its growing popularity. Components such as filters and brushes are widely available from Roborock and third-party sellers. The latter indicates more demand, and more sellers mean lower costs.

I also notice an increase in the availability of batteries. You can purchase replacement batteries from third-party sellers on Amazon. Again, it’s a good sign because of Roborock’s growing popularity, but it still lags behind Roomba with the sheer number of options.

However, I still don’t see many options with more obscure parts like the side brush module or motor, so make sure to keep these components free from hair and dust accumulation so it lasts long.


As with all robot vacuums, the Roborock S4 Max requires some upkeep to function at its best for extended periods.

Here are the parts you need to replace/clean regularly.

  1. Primary brush roll: It’s the most abused part of a robot vacuum. Dirt and hair will wrap on the bristles and axles. Clean this component at least once a week.
  2. Side brush: The newer all-rubber construction bodes well for its longevity, but you’ll have to remove any hair wrapping on the base or around the tentacles to prevent any unnecessary wear.
  3. Dustbin: Empty this container after every run. The HEPA filter is washable, but the best way for longevity is by tapping it on the track bin to dislodge debris and then vacuum with a handheld.
  4. Sensors: Wipe the drop sensors underneath with a clean, dry microfiber towel.
  5. Wheels: Use a clean towel to wipe the wheels (caster and side wheels). You can use a slightly damp towel for heavy accumulation.

Product Specifications

ModelRoomba S4 Max
Battery5,200 mAh Li-ion
Run timeUp to 180 mins.
Water Tank CapacityN/A
Dirt Capacity (dry)460 ml.
Diameter13.8 inches
Height3.8 inches
Smart NavigationYes
Recharge and ResumeYes
HEPA FiltrationYes
Side BrushYes
Extra FilterYes
Manufactured InChina
Warranty1 year
PriceCheck Price

Where can I buy the Roborock S4 Max?

You can buy this robot from online stores like Amazon. Check the link below for more information about the current pricing.

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

Does the Roborock S4 Max provide excellent value?

The Roborock S4 Max may be one of my favorite Roborock products. It provides users with a lot of high-end features packed at a relatively affordable cost. I’d say it’s one of the best value-for-money robot vacuums.

It doesn’t clean embedded dirt as well as a Roomba, but I’ve yet to test a robot vacuum with such. But you’ll get access to more navigational and app features than the more expensive Roomba 980.

Users will have access to features like the invisible wall and no-go zones. So consumers will have lots of options with areas they can block without needing to stop it physically.

It cleans surface dirt as well as any robot vacuum out there, thanks to the higher airflow. The best part is you don’t need to spend a premium for it.

4 Reasons to purchase the Roborock S4 Max

  1. High airflow: The S4 Max’s 20+ CFM score is among the highest in its price bracket.
  2. Premium-level surface debris cleaning: Its high airflow enables it to clean surface debris better than other, more expensive options.
  3. Efficient navigation: Roborock products have evolved into the more efficient navigating robots available, and the S4 Max is no exception.
  4. Reasonable cost: Consumers don’t need to break the bank to enjoy premium-level vacuuming performance from a robot vacuum.

The Verdict: Best Value for Money Roborock

Results are in, and the S4 Max didn’t disappoint. The S4’s successor offers the same high-end performance and affordability, making the older version a popular option among budget-conscious shoppers.

Sure it can’t deep clean as well as a Roomba, but it makes up for it with the rare combination of high-end app features, navigation, and cleaning performance at a more affordable cost.

If you don’t mind not having the mopping feature, then the S4 Max might be the best Roborock option.

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.