Dreame L40S Ultra Review: Powerful Suction, Smart Mopping & Real-World Performance Tested

The Dreame L40S Ultra is the latest release from Dreame and marks the 13th model we’ve tested from this popular brand. Having reviewed over 100 robot vacuums, Dreame consistently stands out for its combination of performance, reliability, and thoughtful design. With the L40S Ultra, we were eager to see how it compares to its bigger sibling, the X50 Ultra, and whether it could live up to Dreame’s reputation for delivering high-quality, feature-packed robots.

Unboxing and First Impressions

Opening the box, it’s immediately clear that Dreame has included everything needed for months of use. Alongside the robot itself, the package contains a multi-purpose cleaning station with its ramp and power cord, mop pads and holders, a bottle of cleaning solution, dust bags, and the usual product literature. Setup is straightforward: plug in the dock, attach the magnetic mop heads, fill the water tank with cleaning solution, and let the robot charge. Once connected to the Dreame Home app, the L40S Ultra is ready to clean.

At first glance, the L40S Ultra looks almost identical to the X50 Ultra, and in many ways, it is. The main differences are the lack of a ProLAP system, no retractable LiDAR, and a slightly smaller 5,200 mAh battery compared to the X50’s 6,400 mAh. Despite these differences, the L40S Ultra performs admirably, proving that high performance doesn’t always require flagship-level features.

Cleaning and Mopping Performance

On hard floors, the mopping system impressed us immediately. The robot handles washing, solution dispensing, and drying almost entirely on its own, while the base station even cleans itself, making the process nearly hands-free. One standout feature is its ability to automatically detach and reattach mop pads at the base station, preventing soggy pads from being dragged across carpets. The mop pads themselves extend into corners and around furniture, and the dedicated cleaning solution tank ensures that the right amount of solution is dispensed every time. While the system lacks ozone water treatment to prevent stagnant water smells, it still delivers a highly effective and low-maintenance cleaning experience.

Vacuuming performance is equally impressive. The L40S Ultra retains Dreame’s detangling duo brush, which resists hair tangles, and features extended side brushes and a mop extension feature. While its climbing system isn’t as advanced as the ProLAP system in the X50, it handles small thresholds and rugs competently. With a suction power of 19,000 Pa—three times the category average—the robot easily tackles pet hair, crumbs, and fine dust. Despite its power, the noise level is moderate at 78 dB on maximum, and quieter modes are available for less disruptive operation. In carpet suction tests, it achieved 490 FPM, well above the average, and real-world cleaning tests awarded it a score of 95 out of 100, outperforming the X50 Ultra by five points despite slightly lower advertised suction.

The Dreame Home App

The Dreame Home app, available on iOS and Android, allows precise control over both vacuuming and mopping. Users can adjust settings, build custom cleaning routines, and target specific rooms or zones. The app also supports multi-floor mapping, no-go zones, and voice control via Alexa and Google Assistant. While it doesn’t include a built-in voice assistant or live video monitoring like the X50 Ultra, it excels in other areas. Features such as intensive carpet cleaning, off-peak charging, side brush activation for carpets, and real-time maintenance tracking make it one of the most thoughtfully designed robot vacuum apps on the market. Though it has a slight learning curve, it quickly becomes intuitive and is, in our opinion, one of the best available.

Customer Feedback and Considerations

Since its release, the L40S Ultra has been well-received, averaging 4.4 stars in reviews. Customers frequently praise its strong suction, efficient mopping, and reliable performance. Some users have noted occasional navigation or mapping inconsistencies, which aligns with our own experience—obstacle avoidance can vary depending on floor type, objects, and room patterns. Price is another common consideration, as it sits at the higher end of its category, though frequent discounts make it a much more appealing value.

Room for Improvement

While the L40S Ultra excels in many areas, it does leave a few features on the table. It does not include a retractable LiDAR system, silver ion or UV modules, electrolyzed water functionality, or the larger battery found in flagship models like the X50 Ultra. These omissions may matter to some buyers, particularly those seeking the most advanced navigation or longest run times.

Final Verdict

Overall, the Dreame L40S Ultra is a well-rounded, high-performing robot vacuum and mop. It combines powerful suction, hands-free mopping, and one of the most user-friendly and feature-rich apps in the category. While it doesn’t include every premium feature of the X50 Ultra, it consistently outperforms expectations in real-world cleaning tests. For those who can find it at a discounted price, the L40S Ultra is one of the best all-in-one robot vacuums available today, offering exceptional value without sacrificing performance.