The Dreame L40 Ultra is a premium robot vacuum with mopping capabilities. It features an extendable side brush and mops for accessing hard-to-reach places. Its mops and side brush can also lift up into the chassis to make vacuuming and mopping in the same cleaning cycle more efficient. It uses an RGB-color camera, a structured light sensor, and a built-in LED light to identify stains and messes and for advanced obstacle avoidance, and it also comes with the usual LIDAR sensor for multi-floor mapping. The base station is versatile, as it empties the vacuum's dustbin, washes and dries the mop with heated water and air, refills the vacuum's clean water tank, and includes a self-washing washboard. This vacuum is compatible with the Dreamehome app, which contains many more customization options and features, and there's support for Alexa, Siri, and Google Assistant.
Our Verdict
The Dreame L40 Ultra offers acceptable performance in a multi-surface household. It does a passable job on bare floors, effectively handling larger debris but missing fine and medium particles as well as patches of floor due to its inconsistent pathing. It's a little better on carpet, though it leaves debris along edges and in corners. Its brushroll doesn't provide enough agitation to deal with fine material in carpet, which also shows in its poor pet hair cleaning performance. Thankfully, its obstacle handling is good despite its odd pathing behavior—it does avoid almost every object it encounters. The full-featured station is pretty good, too, handling most daily maintenance tasks. Its mopping results are acceptable, and it would be better if the pathing were more efficient.
Base station handles day-to-day maintenance.
Effective hazard avoidance system.
Mostly effective in handling large debris on bare floors.
Does alright with larger material on carpet.
Inconsistent pathing adversely effects performance.
Poor debris clearing from flooring cracks.
Drags pet hair around carpet.
Struggles with finer material on carpet.
Brushroll provides insufficient agitation to lift fine debris and pet hair in carpet.
The Dreame L40 Ultra is a passable choice for pet owners. While pet hair pick-up performance is disappointing, as it drags hair around and leaves much behind, stain removal is better but still not great. In both cases, the vacuum's default pathing adversely impacts performance as it needs to roam to position itself (dragging debris along with it) and only moves in a horizontal pattern, meaning stains receive fewer passes overall. But the dock takes care of most of the day-to-day maintenance requirements, and the vacuum is quiet during operation, so your pets shouldn't be too bothered by its presence. There are also many pet-related settings in the app.
Quiet operation.
Solid build quality.
Base station handles day-to-day maintenance.
Poor debris clearing from flooring cracks.
Drags pet hair around carpet.
High recurring costs.
Many parts need periodic cleaning.
The Dreame L40 Ultra's debris pickup performance on hard floors is mediocre. It's effective in dealing with larger debris, but it'll take multiple cleaning cycles to fully clear away large amounts of finer material. The L40's inconsistent pathing can cause it to miss some spots when cleaning small areas, which is something to be aware of if your living space is fairly compact.
Mostly effective in handling large debris on bare floors.
Inconsistent pathing adversely effects performance.
Poor debris clearing from flooring cracks.
The Dreame L40 Ultra delivers alright overall debris pickup performance on low and high-pile carpet. You'll achieve the best results by turning on the 'Side Brush Rotates on Carpet' and 'SideReach' settings. However, you'll probably want the vacuum to run another pass or two to clear away more debris along walls and corners. This vacuum's roller brush also doesn't provide all that much surface agitation on carpeted floors.
Mop and side brush lift function.
Does alright with larger material on carpet.
Poor debris clearing from flooring cracks.
Struggles with finer material on carpet.
Brushroll provides insufficient agitation to lift fine debris and pet hair in carpet.
The Dreame L40 Ultra does a poor job of dealing with pet hair. While it should do just fine with pet hair on bare floors, its brushroll doesn't provide enough surface agitation to lift away hair on carpets, and it also tends to drag some hair around on the latter surface type.
Poor debris clearing from flooring cracks.
Drags pet hair around carpet.
Brushroll provides insufficient agitation to lift fine debris and pet hair in carpet.
The Dreame L40 Ultra offers good overall maneuverability. Its obstacle avoidance system is impressively effective, allowing it to get pretty close to most hazards without running them over. That said, the system can register false positives at times. Unfortunately, it's worth noting that its pathing can sometimes be a little erratic and inefficient, and it might take a little longer to clean your home than some alternatives that move in a more organized fashion.
Effective hazard avoidance system.
Delivers close cleaning around and under obstacles on all floor surface types.
Inconsistent pathing adversely effects performance.
Poor debris clearing from flooring cracks.
Performance Usages
Changelog
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Updated Jan 30, 2026:
We updated the Air Quality box to reflect the fact that this robot vacuum uses an E11 EPA filter.
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Updated Jan 21, 2026:
We mentioned the newly reviewed MOVA P50 Pro Ultra in the Pet Hair Pickup box for users seeking better performance.
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Updated Jul 17, 2025:
We noted the improvement in obstacle avoidance that Dreame made to the follow-up model, the MOVA P10 Pro Ultra. We also added new types of obstacle avoidance technology to the Obstacle Avoidance test box.
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Updated May 01, 2025:
Added mention of the Dreame X50 Ultra, which is an evolution of the L40 Ultra's object avoidance system and works better.
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Differences Between Sizes And Variants
We tested the Dreame L40 Ultra, and there aren't any variants. See our unit's label.
Let us know in the comments below if you come across another variant of this vacuum so that we can update our review.
Popular Robot Vacuum Comparisons
The Dreame L40 Ultra is a premium robot vacuum with mopping capabilities. For users who relish granular customization options and the ability to fine-tune their home's layout, cleaning cycles, and scheduling, this vacuum has a lot to offer. Like other premium models, such as the Roborock Qrevo Curv, this one also features extendable mops and side brushes to deal with traditionally hard-to-reach places for robot vacuums with a circular design, such as along walls and in corners. Unfortunately, despite the depth of its feature set, performance is somewhat lacking. In particular, its pathing yields inconsistent results, and while its obstacle avoidance features are very advanced, they also can be a bit finicky.
See our recommendations for the best robot vacuums for hardwood floors, the best robot vacuums for carpet, and the best robot vacuums for pet hair.
The MOVA P10 Pro Ultra is a better robot vacuum than the Dreame L40 Ultra it's based on, but only if you have mostly hard floors. Dreame has made improvements in the MOVA P10, and it has better hard floor pickup due to its increased suction and better obstacle avoidance due to firmware changes and advancements in AI object recognition. It also has better battery life and better mopping performance. But the MOVA can't use its side brush on carpets, unlike the Dreame, so it can't clean wall edges and corners on carpets. This severely hampers its performance on carpets.
While the Dreame L40 Ultra is the higher-end offering to the Dreame L10s Ultra, the L10s Ultra offers superior performance on every surface type. This upset in performance is attributable to the L40 Ultra's pathing, which yields inconsistent results and adversely impacts debris clearing by dragging debris around and insufficiently covering surfaces. That said, if you want a robot vacuum that offers all the bells and whistles and granular customization options, the L40 Ultra is the vacuum for you.
The Dreame X50 Ultra is an upgrade over the Dreame L40 Ultra. The X50's cleaning performance is slightly improved over the L40's, but the X50's obstacle avoidance is quite a bit better. The X50's excellent low height clearance and threshold clearance represent huge leaps forward for Dreame over the L40 Ultra.
The MOVA P50 Pro Ultra and the Dreame L40 Ultra share similar designs since MOVA is a Dreame sub-brand. Both feature similar self-maintenance docks with hot water mop washing and hot air drying. But despite the shared design DNA, the P50 outperforms the L40 Ultra when it comes to pet hair pickup and hard-floor performance. The L40’s main advantage is that it operates more quietly, but it’s not a significant enough difference to make it a better pick.
Test Results
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