In this comparison, we’ll be looking at two of Roborock’s best value for money options, the S4 and S4 Max.
These two models don’t have any mopping capability, allowing Roborock to bring the price down to mid-level options.
If you look at the features, the S4 and S4 Max have similar characteristics to a higher-end Roomba I and S-Series with the no-go zones and invisible wall. The S4 Max has excellent airflow at over 22 CFM, which is in the level of a
How much did the S4 Max improve over the previous S4? Let’s dig deep and find out in this article.
Introduction to the Roborock S4 and S4 Max
Roborock is rapidly expanding its product line, adding further confusion to consumers, and the S4 Max is the latest.
Please check my guide on the different Roborock models and how each one differs for more information.
The S4 Max probably has the highest airflow I recorded, at over 22 CFM. It’s one of the highest, more than the Roomba 980, which is a few hundred dollars more expensive.
Roborock S4 Max: Best Value for Money Option
This variant is one of Roborock’s least expensive options with the most airflow. One reason why it’s so cheap is it doesn’t have any water tank.
Even if the S4 and S4 Max have the same claimed suction numbers at 2,000 Pascals, the latter has better airflow.
It has the highest of any robot vacuum I’ve tested at its price point, allowing it to pick up debris well, especially on hard floors.
However, performance on carpet isn’t as what I had hoped compared to the S5 Max. The S4 Max didn’t deep clean as well, only picking up 80.1% on average, versus the S5 Max’s 84.55%.
Agitation isn’t as good, so it didn’t do well despite the high airflow. But it was excellent at picking up debris on hard floor. The high airflow enabled it to pick up sand cleanly – with a 99.9% score.
Roborock S4: Lower Airflow But Still Good
Before the S4 Max came out, the S4 was Roborock’s value-for-money king. It was one of the cheapest smart robot vacuums with a combination of features you’ll only find in high-end robots.
When it came out, the S4 was the mid-level option between the S5 and S6. But it was better than the S5 with the upgrades, like the all-rubber side brush and a faster processor.
This is one reason why it’s one of the most popular Roborock options, but its production cycle has come to an end and will be replaced by the S4 Max.
Airflow is decent with 19 CFM, almost as much as other high-end robots like the Neato D7 and Roomba 980.
The high airflow makes the S4 one of the best at picking up surface debris on hard floors and carpets.
However, it isn’t as good in the deep cleaning test, only picking up 72% of sand on mid pile carpet, resulting from the lower airflow.
Similarities of the Roborock S4 and S4 Max
These two models have a lot in common, and we’ll look at it in this section.
The S4 and S4 Max utilize LIDAR and SLAM for navigation. Each will traverse efficiently in straight lines, starting out cleaning the edges before moving to the room’s middle parts.
Roborock products (at least the S-Series) are best at navigation, mainly circumnavigating through tight obstacles. The laser sensor is precise at pinpointing its location and remembering the dock’s location, so it doesn’t get lost.
I’ve tested the S4 Max extensively in this area, and it smoothly navigated around this tight zone without any hiccups.
The S4 has that same capability with navigation and will be efficient at this task.
2. Save Up to 4 Map Levels
Both the S4 and S4 Max can save up to 4 map levels. So any of the two is suitable inside multi-level homes.
What I like about the Roborock app is the quick-start –style method of adding a map. It’s a straightforward approach that makes it easy for users to add subsequent levels.
You can add as many invisible walls and no-go zones to each map as needed.
The beauty of the software is it detects the map automatically with the initial scan. So there’s no need to select the correct map level every time you move to another area.
3. Invisible wall and no-go zones
One of my favorite features available in Roborock is the invisible wall and no-go zones, helping users block off-limit zones.
The invisible wall acts like a wall preventing the robot from going past the virtual lines you set on the map. In contrast, the no-go zone prevents the robot from going into a square or rectangular area.
This combination is enough to seal off most areas in your home not suitable for a robot. It’s a better alternative than having to move a piece of furniture for the same purpose.
4. Side and Combo Brush
Another similarity is the side brush and combo brush. Both robots use an all-rubber side brush and combo brush. I’m not sure if the brush in the S4 Max is denser than the S4, but it looks the same.
The S4 Max and S5 Max main brush are similar in terms of density, so I don’t think its any difference between them.
Both utilize a washable HEPA filter. Since the filter uses a paper material, you’ll have to replace it once every four to six months, depending on the usage frequency.
All Roborock S-Series robots have similar dimensions at 13.8″ wide and 3.8″ tall. It will fit under furniture with a 4″ clearance.
7. Run Time
The S4 and S4 Max use the same 5200 mAh Li-ion battery and will run for up to 180 minutes in quiet mode.
Differences between the S4 and S4 Max
I’ll highlight the differences between these two robots in this section.
While the S4 and S4 Max use the same brushes, the main brush’s placement is different.
The S4’s brush is slightly closer to the front than the S4 Max. FYI, all Roborock S-Series robots starting with the S5 Max have the same side and combo brush placement.
It seems like Roborock is standardizing their design with future releases, and you can see this trend with the S4 Max with the main brush closer to the back of the side wheels.
The S4 Max has the highest airflow so far of all the Roborock robot vacuums I’ve tested so far, with over 22 CFM.
In comparison, the S4 has 19 CFM at the highest setting, which is still plenty for a robot, and at par with Roomba 980 and S9.
3. Dustbin Capacity
The S4 Max has a bigger dustbin at 0.46 liters versus the 0.42 liters in the S4, which is what’s listed on Roborock’s website.
Regardless, you’ll have to empty it often – after every run to prevent spillovers.
App features of the Roborock S4 and S4 Max
Next, we’ll go through the app features for these robot vacuums. The S4 and S4 Max are compatible with the Roborock app, but not with the Xiaomi app.
It’s not an issue as Roborock has added the room naming feature previously absent.
1. Save up to four map levels
Users can save up to four map levels in all S-Series. I like Roborock’s version as the map detect feature, where the algorithm will automatically select the correct floor plan after the initial scan.
These two options are the only alternatives at this price range I’ve tested so far with this technology built-in. Other brands like Viomi don’t, so you’ll have to select manually.
Furthermore, creating a new map is straightforward with the quick-start-type interface. If you use this feature, the robot automatically does a single pass run to scan the area’s layout.
It’s one of the most user-friendly, in my opinion.
2. Invisible wall and no-go zones
These two variants are some of the least expensive options with this containment combo. These are flexible enough to block nearly every off-limit zone inside your home.
An invisible wall is a virtual line drawn on the map that blocks the robot like a wall. The ability to create vertical, horizontal, and diagonal lines makes it very useful.
The no-go zone enables users to draw boxes on the map to mark them as off-limit areas. It’s an excellent tool to block the robot from going over an area rug with tassels if it’s too big to move.
3. Four power settings
Currently, all Roborock robot vacuums have four power levels, which is one less than the previous app versions that had five.
These robots have enough airflow (particularly the S4 Max) that’s usable even in the lowest setting.
This provides flexibility to use the lower settings to preserve battery life (as well as lower noise output) and still achieve the same results on hard floors.
4. Carpet boost
The Roborock app also has carpet boost, which increases suction when it detects carpet automatically.
This feature eliminates having to adjust suction manually and excellent in homes with a mix of hard floors and carpets.
5. Custom room naming
One of the recent (and critical) Roborock app updates is the room naming feature’s addition. This feature is absent previously and a reason why I prefer using the Xiaomi app.
What I like about this feature is it’s compatible with Alexa. So you could say Roborock, please clean the dining room, and these robots will clean the area you name “dining room.”
Alexa users should consider these two robots if they’re looking for a mid-priced smart robot vacuum.
6. Unlimited scheduling
You can schedule unlimited runs with the S4 or S4 Max with the option to select weekdays or weekends.
The ability to schedule as many runs as needed is beneficial for busy folks, who could just set the vacuuming schedule for the week then empty the bin after coming home from work.
This tab provides users a heads up when to change components like the filter, side brush, and combo brush. It’s a time-based system, so you still have to check each part if it needs cleaning or replacing visually.
Despite having the same suction numbers, the S4 Max has more airflow with over 22 CFM at the max setting.
In comparison, the S4 tops out at 19 CFM – still a decent number and one of the highest scores at its price bracket. The Roborock E4 has a higher airflow score than the S4.
Both the S4 and S4 Max have excellent cleaning dynamics, so picking up surface dirt won’t be an issue.
Here’s the result of the S4 Max, which I tested a few weeks back.
- Overall: 94.45%
- Hard floor: 99.7%
- Carpet (surface debris): 98%
- Sand on hard floor: 99.9%
- Deep cleaning: 80.2%
The S5 Max’s high airflow makes it an excellent hard floor cleaner. Even with though to clean sand, it picked up an excellent rate of 99.9%, gobbling most of it after the first pass.
In my YouTube review, you’ll see how well the S4 Max picks up sand – better than the S5 Max.
It has sufficient airflow even in the lower range, so you don’t have to leave it at Max to clean well.
The S4 has the same qualities but a touch lower.
Which is better on hard floors?
It’s really close, but the S4 Max’s higher airflow gives it the nod for hard to clean stuff like sand.
However, it shouldn’t matter for daily cleaning tasks as both variants will do quite well at picking up dust and hair.
Also, the side brush doesn’t spin as fast as a Roomba – it won’t scatter as much debris.
Edge cleaning comparison
Roborock’s S-Series robots are excellent at cleaning edges for a round-shaped robot. The S4 Max is the best I’ve tested so far, picking up the most.
I could point to the high airflow, allowing it to pick up more after every pass. It’s not totally clean, but there’s only minimal debris left.
Hair wrap comparison
To check how well robot vacuums resist tangles, I scattered one gram of five and seven-inch hair strands. The S4 Max picked up a decent chunk – 80% from both the five and seven-inch test.
Again, the high airflow is a significant reason why the S4 Max did well.
I don’t have the S4, so results aren’t available, but it’s decent based on reviews I’ve seen.
Which is better on carpets?
One area you’ll feel the S4 Max’s airflow advantage is on carpet, particularly in cleaning embedded dirt, where it picked up an average of 80.2%. The S4’s score is 72%, which is decent, but I was expecting more because of its above-average airflow.
The S4 Max picked up an average of 80.2% versus the S4’s average of 72% – still a decent score for a non-Roomba product.
Between the two, the S4 Max is better for cleaning carpet. Still, it’s surprisingly inferior to the S5 Max, probably because the latter has better agitation as it sits lower to the ground.
Run time comparison
Both the S4 and S4 Max utilize a 5200 mAh Li-ion battery and will run for up to 180 minutes in quiet mode. Roborock seems to tweak their algorithm to standardize the run time numbers as all S-series robots have the same claimed number.
Regardless, since Roborock’s smart robots have recharge and resume, run time shouldn’t be an issue as it resumes cleaning if it doesn’t finish the task previously.
So unless you live in a large mansion, this shouldn’t be a concern.
The S4 produced more noise with 71 decibels at the highest setting. In comparison, the S4 Max maxed out at 64.1 decibels at the highest setting.
These robot vacuums need a level of maintenance to function efficiently. I’ll enumerate the different items you need to check on occasion.
- Primary brush: Both the S4 and S4 Max utilize a combo brush with a blade and bristled part. Remove any hair wrapping around the bristles and axles to prevent unnecessary friction.
- Side brush: The new all-rubber side brush provides better durability. But you’ll have to remove any hair that may wrap around the base. Wipe it on occasion with a slightly damp towel to remove and dirt sticking on it.
- Dustbin: Empty the dustbin at least once daily.
- HEPA filter: Roborock’s HEPA filter is washable. I don’t wash mine but instead tap it on a solid surface to dislodge debris stuck on the folds, then vacuum with a handheld.
- Wheels: Use a clean microfiber towel to wipe the side and caster wheels.
- Drop sensors: There are four drop sensors underneath, preventing the robot from falling from cliff zones. Keep these sensors clean by wiping them using a clean microfiber towel.
- Exterior: Give the exterior a wipe down with a clean towel.
Roborock S4 Max
|Run time (Turbo mode)|
|Recharge and Resume|
|Number of Maps|
|Water tank capacity|
Other Roborock comparisons
- Roborock S4 Max vs S5 Max
- Roborock S5 Max vs S6 MaxV
- Viomi V3 vs Roborock S5 Max
- Roborock S7 vs S6 MaxV vs S5 Max
Where can I buy these robots?
You can purchase the Roborock S4 and S4 Max from online stores like Amazon. Take note that the Roborock S4 has been discontinued and may not be available. If it is, the price may exceed the S4 Max.
The Roborock S4 linked above is a refurbished unit, meaning it isn’t brand new, but it’s much cheaper. One concern for me when buying such is how well the battery holds up and the shorter 90-day warranty. If these are not issues, then try it out and see if it’s a good fit.
Disclaimer: I will earn a commission if you purchase from any of these links, but at no extra cost to you, so it’s a win-win for us!
Which is better, the Roborock S4 or S4 Max?
The S4 Max took the strengths of the S4 and enhanced it with its higher airflow, larger dustbin capacity, and better overall performance.
Like the S4, it’s excellent on hard surfaces while being decent for carpet.
The higher-end airflow makes it an excellent option for cleaning stuff like sand.
4 Reasons to choose the Roborock S4 Max
- Cheaper than the S4: Surprisingly, the S4 Max is less expensive with the S4’s current pricing inflated because it’s no longer in production.
- High airflow: It has high-end airflow, more than the Roomba 980.
- Smart navigation: Roborock products are known to manufacture some of the smartest navigating robot vacuums. The S4 Max is no exception.
- Excellent at cleaning sand: The high airflow of the S4 Max enables it to clean sand well.
3 Reasons to choose the Roborock S4
- Value for money: When Roborock introduced the S4, it was one of the least expensive robot vacuums with high-end airflow, precision navigation, and excellent surface debris pick up.
- Extended run time: The S4 will run for up to 180 minutes – it covers a lot of ground. With recharge and resume, this robot is usable inside larger spaces.
- Decent for cleaning carpet: Expect above-average surface pick up and average performance in cleaning embedded dirt.
The Verdict: Roborock S4 is Good, But the S4 Max is Better
While the S4 and S4 Max have many similarities, the S4 Max is the better product overall. This model has more airflow, a larger dustbin, which picks up more debris, especially hard to clean stuff like sand.
Furthermore, the S4 Max is cheaper than the S4 (brand new price) if you look at the current pricing, and for me, this seals the deal.
The Roborock S4 has been discontinued, and the only option is to go for the S4 Max if you don’t need the mopping functionality.