Help me choose
A stronger Pool Express option
Dolphin Liberty 400 and Dolphin S50 are compared feature by feature below. For a stronger Pool Express option, consider Dolphin Cayman. Inground and above-ground pools up to 40 ft that need floor and wall cleaning.
Liberty
Dolphin Liberty 400
Inground and above-ground pools up to 33 ft that need floor, wall and waterline cleaning without a cord.
What we recommend instead
Dolphin Cayman
Inground and above-ground pools up to 40 ft that need floor and wall cleaning.
$1,079
Buy Dolphin CaymanDolphin Liberty 400 or Dolphin S50: our take
Dolphin Liberty 400 and Dolphin S50 are compared on pool fit, cleaning reach, debris handling, controls and ownership details. The recommendation is based on the job the robot must do—not a simple feature count.
Pool fit and cleaning reach
Dolphin Liberty 400 is intended for inground and above-ground pools, while Dolphin S50 is intended for above-ground pools. Dolphin Liberty 400 is rated for pools up to 33 ft; Dolphin S50 is rated up to 30 ft. Dolphin Liberty 400 cleans floor, walls, and waterline; Dolphin S50 cleans floor. Dolphin S50's documented cleaning system includes 1 active brush.
Filtration and debris
Dolphin Liberty 400 includes Basket and UltraFilter; Dolphin S50 includes Basket. That gives Dolphin Liberty 400 the clearer documented edge for fine silt, pollen and sand.
Controls and day-to-day ownership
Dolphin Liberty 400 provides a weekly timer and smartphone control; Dolphin S50 provides one-touch starts and power-supply controls. Dolphin Liberty 400 uses cordless battery power, while Dolphin S50 uses a 40 ft corded cable. Dolphin Liberty 400 is listed at 17.9 lb versus 14 lb for Dolphin S50; that 3.8999999999999986 lb difference matters when lifting the robot from the pool.
Price, warranty and the decision
Dolphin Liberty 400 is listed at $1,429 and Dolphin S50 at $649; Dolphin S50 is $780 less. Dolphin Liberty 400 lists a 3-year warranty compared with 2 years for Dolphin S50. Dolphin Liberty 400 and Dolphin S50 each have a specific fit, but neither is the Pool Express pick for this job. Our better alternative is Dolphin Cayman. Inground and above-ground pools up to 40 ft that need floor and wall cleaning.
Feature check: what each robot actually has
A green check means the feature is documented as included. A red X means it is documented as absent. A dash means the source does not make the feature clear.
| Feature | Dolphin Liberty 400 | Dolphin S50 |
|---|---|---|
| Cleans the pool floor | Yes | Yes |
| Climbs and cleans walls | YesEdge | No |
| Scrubs the waterline | YesEdge | No |
| Fine-debris filter included | YesEdge | No |
| Large-debris filter | Yes | Yes |
| Automatic scheduling | YesEdge | No |
| Smartphone app | YesEdge | No |
| Anti-tangle swivel | Not listed | Not listed |
| 3-year warranty | YesEdge | No |
| No recharging between cycles | No | YesEdge |
| Built-in UV-C water treatment | No | No |
Unknown is not treated as “no.” Specifications come from the product pages, current catalog records and manufacturer material collected for this site.
Where Dolphin Liberty 400 stands out
Dolphin Liberty 400 is the better fit for owners who value cordless handling more than automatic scheduling and continuous power.
- Cleans the floor, walls and waterline instead of stopping below the tile line
- Includes filtration for sand, pollen and other fine debris
- Can start on a weekly schedule without a manual launch before every cycle
- Adds smartphone control
Where Dolphin S50 stands out
Dolphin S50 is the better fit for shoppers prioritizing the lower $649 starting price.
- Runs from continuous plug-in power without a recharge between cycles
- Is listed $780 lower
- Weighs 14 lb versus 17.9 lb
Dolphin Liberty 400 vs Dolphin S50 specifications
Use pool fit first. Price and app control do not make up for a robot that cannot cover the length or surfaces you need cleaned.
| Specification | Dolphin Liberty 400 | Dolphin S50 |
|---|---|---|
| Best fit | Inground and above-ground pools up to 33 ft that need floor, wall and waterline cleaning without a cord. | Above-ground pools up to 30 ft that need floor cleaning. |
| Starting price | $1,429 | $649 |
| Pool type | Inground, Above-ground | Above-ground |
| Maximum pool length | Up to 33 ft | Up to 30 ft |
| Cleaning coverage | Floor, Walls, Waterline | Floor |
| Power | Cordless | Corded |
| Filtration | Basket, UltraFilter | Basket |
| Scheduling | Weekly schedule + app | One-touch start |
| App and remote | App control | Power-supply controls |
| Cable | Cordless | 40 ft |
| Robot weight | 17.9 lb | 14 lb |
| Warranty | 3 years | 2 years |
Consider the stronger Pool Express option
Dolphin Liberty 400 and Dolphin S50 are compared feature by feature below. For a stronger Pool Express option, consider Dolphin Cayman. Inground and above-ground pools up to 40 ft that need floor and wall cleaning.
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