The evolution of robotic pool cleaning technology has led to a distinct divide between cordless freedom and wired power and intelligence. At the forefront of this divide are two standout models from Maytronics Dolphin: the Dolphin Liberty 400 vs Dolphin S400. Each brings exceptional capabilities to the pool, but they’re built with different priorities in mind. One is designed to liberate users from cables, while the other is built for power users demanding maximum control and runtime.
This comprehensive comparison covers everything prospective buyers need to know about these two premium robotic pool cleaners. From cleaning performance, surface reach, smart features, brush technology, filtration efficiency, to battery management and app connectivity, we examine every detail that separates the Dolphin Liberty 400 from the Dolphin S400.
Contents
Differences Between Dolphin Liberty 400 vs Dolphin S400
Power Source and Operational Flexibility
The Dolphin Liberty 400 is a true embodiment of cordless design. Powered by a lithium-ion battery, it runs for up to 90 minutes on a single charge. This runtime is optimized for pools up to 10 meters (33 feet). Charging is handled via a magnetic induction dock that provides safe, waterproof contact points. Once the cleaning session is complete, the unit can be summoned to the waterline using the ClickUp™ retrieval system, which raises the handle for easy removal.
The Dolphin S400, by contrast, uses a corded power supply with a 60 ft swivel cable. There are no time limits or charge cycles to worry about. It can run multiple cleaning sessions back-to-back without any interruptions or downtime. The power cable is tangle-resistant and managed easily through the included transport caddy.
Winner: Dolphin S400
With unlimited runtime and no battery restrictions, the S400 offers superior long-session reliability—especially for larger pools or intensive cleanings.
The Liberty 400 uses CleverClean™ scanning and a gyroscopic sensor to create smart cleaning patterns. This system ensures efficient floor and wall coverage and allows the robot to climb the pool walls and maintain orientation, especially on vertical and angled surfaces. It’s intelligent and consistent for standard-shaped pools.
The S400 uses SmartNav™ mapping with multi-directional sensors, allowing it to learn and adapt to the pool’s geometry in real time. It avoids repetitive passes, optimizes pathing based on previous runs, and navigates uniquely shaped or obstacle-rich pools with enhanced precision.
Winner: Dolphin S400
Its more advanced navigation system ensures better route optimization, particularly in freeform or custom pools.
Cleaning Coverage: Floor, Walls, and Waterline
Both the Dolphin Liberty 400 and Dolphin S400 are engineered for full pool cleaning, meaning they can scrub the floor, walls, and waterline. The Liberty 400 performs well in all three zones thanks to its gyroscopic control, but to preserve battery life, its cycles are timed, and waterline contact may be limited in duration.
The S400 has no such limitations. It spends significant time on the waterline, maintaining strong adhesion and ensuring a more complete clean of that problem-prone zone where oils, scum, and dirt tend to accumulate.
Winner: Dolphin S400
With unrestricted cycle time and enhanced waterline scrubbing algorithms, it delivers more consistent cleaning at all pool levels.
Brush Technology and Debris Removal
The Liberty 400 uses dual active front scrubbers, rotating at high speeds to loosen debris from vinyl, fiberglass, and plaster surfaces. Its brushing capability is strong for a cordless unit and does an excellent job on flat areas and moderate inclines.
The S400 features dual active scrubbers at both the front and rear, which provides non-stop contact with the pool surface regardless of the robot’s movement direction. This results in deeper scrubbing action on persistent algae, biofilm, and scaling.
Winner: Dolphin S400
With dual-directional brush engagement, it leads in mechanical debris agitation and surface sanitization.
Filtration System and Debris Handling
The Dolphin Liberty 400 uses a fine cartridge filter that’s top-loading and easy to rinse. It efficiently captures leaves, dust, and sand but does not support interchangeable filter options.
The Dolphin S400, by contrast, offers a multi-layer interchangeable filter basket, allowing users to switch between fine and ultra-fine filters based on the season or pool condition. This gives users better control over filtration precision and improves cleaning results in pools with pollen, sediment, or micro-debris.
Winner: Dolphin S400
Interchangeable filtration makes it more adaptable and effective across different debris types.
Smart Features and App Control
The Liberty 400 connects via Bluetooth to the MyDolphin™ Plus App. Within range, users can start and stop cleaning cycles, select between Standard, Eco, or Cycle Selector modes, and schedule sessions. However, since Bluetooth is range-dependent, it requires proximity to the robot to function.
The S400 uses Wi-Fi, offering complete remote access from anywhere. It supports more detailed scheduling, real-time alerts, firmware updates, and more precise control of cleaning cycles through the app—even when you’re away from home.
Winner: Dolphin S400
Wi-Fi connectivity allows complete remote management and deeper customization for modern smart home integration.
Handling, Weight, and Storage
The Liberty 400 weighs 18.5 lbs and includes the innovative ClickUp™ system, which prompts the robot to raise its handle for easy retrieval from the water. This design eliminates the need to pull cables or bend over repeatedly, making it extremely ergonomic.
The S400, while heavier at 24.6 lbs, comes with a deluxe transport caddy for storage and mobility. However, retrieval is manual via the cable, which can be more cumbersome, especially after longer sessions.
Winner: Dolphin Liberty 400
With cordless design and ClickUp™ technology, it provides a more convenient and user-friendly handling experience.
Cable Design and Mobility
The Liberty 400, being cordless, eliminates all concerns about tangling, cable storage, or reach limitations. It navigates freely without drag and is ideal for smaller pools or for users who dislike managing cords.
The S400 includes a swivel cable that prevents tangling, but it still requires thoughtful handling and proper storage after each session.
Winner: Dolphin Liberty 400
Complete cordless mobility is unmatched in ease and flexibility, especially in compact pool environments.
Quick Rundown Of Dolphin Liberty 400
Quick Rundown Of Dolphin S400
Conclusion
Choose the Dolphin Liberty 400 if you value cordless convenience, ergonomic handling, and a simplified cleaning experience for smaller residential pools. Its Bluetooth control, lightweight build, and ClickUp™ lift system make it perfect for pool owners who prioritize freedom of movement and modern ease-of-use without the need for continuous cleaning.
Choose the Dolphin S400 if you want a robust, high-performance robotic cleaner with superior filtration, dual-directional scrubbing, unlimited runtime, and remote Wi-Fi control. It’s designed for tech-savvy pool owners who demand precision, reliability, and deep customization for maintaining pristine water quality.
Overall Winner: Dolphin S400
With unmatched power, filtration versatility, advanced navigation, and full remote control, the Dolphin S400 delivers a best-in-class cleaning experience for users seeking comprehensive, intelligent pool maintenance. For those who want the smartest and most thorough cleaner available, the S400 stands at the top.