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Dreame L40 Ultra Review – The Feature-Rich Robot Vacuum You Need to Know About

Welcome to our in-depth review of the Dreame L40 Ultra Robot Vacuum Mop Combo. After purchasing the L40 Ultra and putting it through a series of rigorous evaluations over the past few weeks, we believe it’s one of the best robot vacuums we’ve evaluated recently. It not only outperformed the more expensive Dreame X40 in almost every category but also boasts nearly every new feature available on modern robot vacuums today.

Dreame L40

The Dreame L40 Ultra provides advanced cleaning with up to a month of hands-free operation, achieving perfect debris pick-up in tests. It empties into a 60-day bin, refills water for 30 days, and cleans and dries its mop pad after each session. With Intelligent PowerDetect technologies like DirtDetect and StainDetect, it targets hidden dirt and stains, adjusting to floor types. NeverStuck technology and 360° LiDAR enable precise obstacle navigation, and it lifts the mop pad over carpets. See additional info

$1,099.99 $1,499.99

Price as of July 3, 2025

Auto Empty Station: Self Empties Debris | Washes Mop Pad | Washes Mop Pad with Hot Water | Dries Mop Pad | Dries Mop Pad with Heated Air| Self Cleaning | Dirty Water Sensor

Mopping: Lifts Mop Pads on Carpets | Extending Mop Pad for Hard to Reach Areas | Can Leave Pads At Base while Vacuuming

Hardware: Auto Extending Side Brush for Hard to Reach Areas | 22mm Threshold Crossing | Removes Hair from Brush Roll

Performance: Carpet Boost Settings

Mapping / Navigation: Multi Level Maps | Virtual Barriers and No Go Zones

Obstacle Avoidance: 100 Objects Recognized

Pet Features: Live Video Monitoring

ScoresDreame L40Average Robot Vacuum Tested
Vacuum Wars Overall3.76

2.80

Features4.20

3.63

Mopping Performance3.30

2.73

Obstacle Avoidance4.38

3.44

Pet4.32

2.87

Navigation4.14

3.00

Battery4.06

2.27

Performance3.97

3.59

Official Battery Life: 194 MinutesNavigation Type: Spinning Lidar
Official Suction Power: 11000 PaDust Bin Size: 350ml
Obstacle Avoidance Type: Structured Light, Single Camera, & Crossed Infrared beamsObjects Recognized: 100
Multi Level Maps: YVirtual Barriers: Y
Detergent Capacity: UnknownDisposable Bag: 3.2L

There are some important potential drawbacks to consider about this robot vacuum, as you’ll see shortly. But unless major quality control issues arise in the future, the Dreame L40 is poised to rank very high for a long time on the Vacuum Wars Top 20 Robot Vacuum list. So, let’s dive into the details and see what makes the Dreame L40 stand out.

Dreame L40 vs. Dreame X40

The Dreame L40 and the older, more expensive Dreame X40 are very similar machines. However, the L40, which we’re reviewing today, is significantly more affordable.

Side-by-side view of Dreame L40 Ultra in white and Dreame X40 Ultra in black, showcasing design and dock differences.
Dreame L40 Ultra design comparison to the Dreame X40 Ultra. © Vacuum Wars

The main differences between the two models are that the X40 has slightly more official suction power and slightly hotter water to wash its mop pads.

Official suction power comparison: Dreame L40 Ultra with 11,000 pa and Dreame X40 Ultra with 12,000 pa. An arrow indicates the X40 Ultra has stronger suction.
X40 Ultra pulls slightly ahead in suction. © Vacuum Wars
Comparison of mop washing temperatures: Dreame L40 Ultra uses 149°F water while Dreame X40 Ultra uses 158°F.
Both units use hot water, but X40 runs slightly hotter. © Vacuum Wars

Despite these minor differences, the L40 offers almost identical features to the X40, with very few obvious exceptions.

Dreame L40 Pros

Outstanding Vacuuming Performance

The Dreame L40 excels at the fundamentals of vacuuming hard floors and carpets. It effortlessly swept up all the debris we evaluated it with on both surfaces. Moreover, it performed above average in deep cleaning carpets, effectively removing deeply embedded debris like sand. The L40 achieved essentially the same score as the X40.

Carpet deep clean test results: Dreame L40 Ultra scored 81, Dreame X40 Ultra scored 80, and the average robot vacuum scored 77. Images show L40 Ultra on both hard and carpeted test surfaces.
Dreame L40 Ultra’s vacuuming and carpet deep cleaning performance. © Vacuum Wars

Innovative Side Brush and Suction Power

One notable feature is its automatically extending, liftable side brush. It’s a rare addition that significantly improves its ability to sweep debris from corners.

In our evaluations, its suction power was above average, as was its airflow. Both numbers closely mirror those of the Dreame X40.

Close-up of Dreame L40 Ultra using its extending side brush to clean debris from the edge of a floor along a wall.
L40 Ultra’s side brush tackles edge debris. © Vacuum Wars
Comparison of suction and airflow performance between Dreame L40 Ultra (0.86 kpa, 21 cfm), Dreame X40 Ultra (1.03 kpa, 20 cfm), and the average robot vacuum (0.75 kpa, 16 cfm).
Dreame units outpace the average in both kpa and cfm. © Vacuum Wars

Exceptional Battery Life

The L40 Ultra boasts an impressive battery life. Dreame claims it can run for 194 minutes on low power, which is higher than average. In our battery efficiency evaluation, where we run the vacuum on different power settings over a fixed floor plan, it achieved the highest score we’ve seen yet. It got an average of 2.2 minutes per percentage point, nearly double the average amount.

Battery efficiency comparison showing Dreame L40 Ultra at 2.20 minutes per 1% (highest score on record), Dreame X40 Ultra at 1.59 minutes, and the average at 1.28 minutes.
Longest runtime per charge among evaluated bots. © Vacuum Wars

Superior Mopping Abilities

Mopping is another area where the L40 shines. It uses two spinning mop pads with electronically controlled water dispensing to clean hard floors. The mop pads automatically lift up 10.5 mm when the vacuum senses carpets. This keeps your carpets dry and enables the robot to mop hard floors and vacuum carpets in the same run, dramatically improving efficiency.

Close-ups of Dreame L40 Ultra's dual spinning mop pads. Left shows bottom view; right shows the pads from a side angle, with vacuum units on shelves in the background.
The Dreame L40 Ultra utilizes spinning mop pads that can automatically lift up to 10.5mm when sensing carpets. ©Vacuum Wars

Additional mopping features include MopExtend, where the mop pad automatically extends for better coverage, and RoboSwing, used to get under some hard-to-reach places. Both features can be turned on and off or modified in the app.

Split image showing Dreame app settings with "AI-driven MopExtend" highlighted on the left, and L40 Ultra mopping tightly along floor edges on the right.
Dreame L40 Ultra’s MopExtend RoboSwing technology is controlled through the app. ©Vacuum Wars

Like the X40, the L40 allows you to leave the mop pads behind when vacuuming carpets, using a series of magnets. This ensures the mops won’t get the carpets wet. And in our new dried-on stain mopping evaluation, the L40 outperformed the X40, scoring 119, which is higher than average and significantly better than one of the leading electric floor mops, the Bissell CrossWave.

Left: Inside view of Dreame L40 Ultra's base station showing mop pad cleaning area. Right: L40 Ultra robot vacuum cleaning a white surface under bright lighting, with multiple other robot vacuums displayed on the wall behind.
The Dreame L40’s automatic mop pad removal feature. ©Vacuum Wars
Dried-on mopping test results: Dreame L40 Ultra scored 119, Dreame X40 Ultra scored 72, Bissell Crosswave Pet Pro scored 78, and the average is 103.
Dried-on stain mopping performance. ©Vacuum Wars

Advanced Automated Charging Station

Another significant advantage of the L40 is its automated charging station. In addition to automatically emptying its dustbin into the included bag, it washes its mop pads with hot water, dries them with hot air, and refills the mop tank with clean water and a cleaning solution of your choice.

The charging base also features a rare self-cleaning mechanism, utilizing a mechanical tray with spinning squeegees to keep the bin clean from hair and debris.

A 4-panel view of Dreame L40 Ultra’s base station: inserting a water tank, waste bag compartment, internal water nozzles, and the removable cleaning tray.
Dreame L40 Ultra’s hands-free automated base station ©Vacuum Wars

Effective Obstacle Avoidance Technology

The L40’s obstacle avoidance technology is impressive. It uses a camera, structured light, and crossed infrared beams to recognize and avoid household objects. An LED light on the front allows the camera to see in dark places.

In our five obstacle avoidance evaluations, including our new torture assessment, the L40 was significantly above average, tying for second place overall in the obstacle avoidance category. While the Dreame X40, which uses a slightly different system, slightly outperformed it in this area, the L40 was very close behind.

Obstacle avoidance test showing Dreame L40 Ultra navigating a cluttered room. Scoreboard comparison shows Dreame L40 Ultra scoring 21, Dreame X40 Ultra scoring 22, and the average robot vacuum score as 17.
Dreame L40 Ultra’s obstacle avoidance technology and performance ©Vacuum Wars

Reliable Navigation and Mapping

In terms of navigation, the L40 performs well. It uses a spinning LIDAR sensor on top to map and navigate around your home. In our evaluations, it was slightly above average in efficiency and coverage. It consistently mapped our floor plan in about 5 minutes and vacuumed and mopped in about 43 minutes, faster than the average of 66 minutes.

We did notice it missed one of the rugs on the floor plan consistently, possibly due to it being a longer pile rug. Adjusting settings in the app might resolve this issue.

Test results comparing Dreame L40 Ultra’s total cleaning time and navigation efficiency. For 387 sq. ft., the L40 Ultra completed cleaning in 43 minutes vs. X40 Ultra at 59 minutes and average bots at 66 minutes. Navigation efficiency: L40 Ultra at 0.70 m²/min vs average 0.66 m²/min.
Shortest mop + vacuum duration in its class. © Vacuum Wars

Feature-Rich App

The Dreame app is another highlight, offering all the features of its main competitors. It includes virtual barriers and extensive customization options, such as how frequently it empties its dustbin or washes the mop pads—useful for homes with pets.

Speaking of pets, it also offers live video monitoring using its camera, allowing you to check on your pets without the vacuum running. The app has a great score on the iOS store, though it has a lower rating on the Android store for some reason.

Two smartphone screens displaying the Dreame L40 Ultra app interface. One shows map editing features, while the other shows a live cleaning camera view with manual control options.
Dreame L40 Ultra’s app comes with lots of features. ©Vacuum Wars
App store ratings for the Dreame L40 Ultra compared to average ratings. On iOS, it scores very well, but on Google Play, it scores mid.
The app’s performance varies by platform. © Vacuum Wars

Dreame L40 Cons

Hair Tangling Issues

Despite its many strengths, the L40 does have some drawbacks. We’re currently developing a new system to score robot vacuums on pet hair pickup and hair tangles, and the L40 did not perform well in these new evaluations. In fact, it had more hair tangled on the 7-inch hair assessment than any other robot we’ve evaluated so far, and it wasn’t particularly effective at picking up pet hair from carpets.

Hair performance tests: L40 Ultra with Tricut Brush achieved 0% hair tangle (vs 51% average) and 82% hair pickup (vs 71% average) in two categories.
The Dreame L40 Ultra struggled with hair pickup and hair tangles. ©Vacuum Wars

Fortunately, there’s an easy solution. Dreame sells the Tri-cut brush separately for the L40. When we used the Tri-cut brush, it achieved the best scores on these new evaluations among all robots we’ve assessed. If you have pets and deal with a lot of hair, purchasing the Tri-cut brush is a significant upgrade.

Side-by-side hair performance results for Dreame L40 Ultra using the optional Tricut brush: 0% hair tangle compared to 51% average in the 7" hair tangle test, and 82% hair pickup on carpet versus a 71% average in the 2.5" hair pickup test.
The Dreame L40 Ultra’s optional Tricut brush performed better than the standard brushroll. ©Vacuum Wars

Noise During Mop Pad Washing

Another issue we experienced was an odd noise when the L40 was washing its mop pads—a lot of squeaking, which we assumed was coming from the self-cleaning mechanism. It might need oil or maintenance. Since the L40 is so new, we can’t confirm if this is an isolated issue or a common problem. Hopefully, as more reviews come out, we’ll get a clearer picture and possibly a fix.

Three images show Dreame L40 Ultra’s self-cleaning dock in detail. Top left: robot docked with the rear facing a drain slot. Top right: interior with twin waste ports and nozzle. Bottom: full underside cleaning tray with dual rotating arms and a center squeegee.
The Dreame L40 Ultra’s self-cleaning mechanism was making odd noises during washing. ©Vacuum Wars

Conclusion

After tallying all the scores, the Dreame L40 is currently ranking number two on our Top 20 Best Robot Vacuums list, which is an amazing achievement given its price point. We wouldn’t be surprised if it overtakes the number one spot soon when we update our algorithm to include the new evaluations.

Final Thoughts

The Dreame L40 Robot Vacuum Mop Combo is an outstanding machine that offers premium features at a more affordable price than its predecessor, the X40. While it has some minor issues, particularly concerning hair tangling, these can be mitigated with the Tri-cut brush accessory. Its exceptional vacuuming and mopping performance, advanced obstacle avoidance, and convenient automated charging station make it a strong contender for the best robot vacuum on the market.

$1,099.99 $1,499.99

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Christopher White

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Christopher White CEO
Christopher White is the CEO of Vacuum Wars, the premier YouTube channel dedicated to vacuum cleaner reviews. Over the past eight years, Vacuum Wars has become a trusted resource, meticulously reviewing hundreds of robot vacuums, cordless vacuums, carpet cleaners, and various floor care products. Known for their comprehensive in-house testing, Vacuum Wars has built one of the most extensive databases of vacuum cleaner metrics available. Under Christopher’s leadership, the channel has maintained a strict no-sponsorship policy, ensuring that all reviews remain unbiased and trustworthy. This dedication to integrity has garnered a loyal following of over 300,000 subscribers who rely on their expert advice. Christopher is also a recognized authority on robot vacuums, boasting one of the largest private collections of these devices worldwide. Learn more.

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