Robotic pool cleaner comparison

Dolphin S50 vs Dolphin T25

A side-by-side comparison of pool fit, cleaning coverage, filtration, controls and the better Pool Express option.

By Brian Williamson, Pool Express product specialist
Updated November 9, 2026

Better alternative

A stronger Pool Express option

Dolphin S50 and Dolphin T25 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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S-Line

Dolphin S50

Above-ground pools up to 30 ft that need floor cleaning.

Listed price $649

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T-Line

Dolphin T25

Inground and above-ground pools up to 33 ft that need floor and wall cleaning, with fine debris.

Listed price $849

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A better alternative

What we recommend instead

Pool Express pick

Dolphin Cayman

Inground and above-ground pools up to 40 ft that need floor and wall cleaning.

$1,079

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Buying guidance

Dolphin S50 or Dolphin T25: our take

Dolphin S50 and Dolphin T25 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 S50 is intended for above-ground pools, while Dolphin T25 is intended for inground and above-ground pools. Dolphin S50 is rated for pools up to 30 ft; Dolphin T25 is rated up to 33 ft. Dolphin S50 cleans floor; Dolphin T25 cleans floor and walls. Dolphin S50's documented cleaning system includes 1 active brush.

Filtration and debris

Dolphin S50 includes Basket; Dolphin T25 includes Basket and UltraFilter. Dolphin T25 has the clearer documented edge for fine silt, pollen and sand.

Controls and day-to-day ownership

Dolphin S50 provides one-touch starts and power-supply controls; Dolphin T25 provides a weekly timer and power-supply controls. Dolphin S50 uses a 40 ft corded cable, while Dolphin T25 uses a 50 ft corded cable. Dolphin S50 is listed at 14 lb versus 15 lb for Dolphin T25; that 1 lb difference matters when lifting the robot from the pool.

Price, warranty and the decision

Dolphin S50 is listed at $649 and Dolphin T25 at $849; Dolphin S50 is $200 less. Each lists a 2-year manufacturer warranty. Dolphin S50 and Dolphin T25 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 S50	Dolphin T25
Cleans the pool floor	Yes	Yes
Climbs and cleans walls	No	YesEdge
Scrubs the waterline	No	No
Fine-debris filter included	No	YesEdge
Large-debris filter	Yes	Yes
Automatic scheduling	No	YesEdge
Smartphone app	No	No
Anti-tangle swivel	Not listed	Not listed
3-year warranty	No	No
No recharging between cycles	Yes	Yes
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 S50 stands out

Dolphin S50 is the better fit for shoppers prioritizing the lower $649 starting price.

Is listed $200 lower
Weighs 14 lb versus 15 lb

Where Dolphin T25 stands out

Dolphin T25 is the better fit for pools up to 33 ft.

Adds wall climbing and scrubbing
Includes filtration for sand, pollen and other fine debris
Can start on a weekly schedule without a manual launch before every cycle
Is rated for pools up to 33 ft