Robotic pool cleaner comparison

Dolphin T15 vs Niya Sonar 20

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 T15 and Niya Sonar 20 are compared feature by feature below. For a stronger Pool Express option, consider Dolphin Escape. Inground and above-ground pools up to 30 ft that need floor cleaning.

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T-Line

Dolphin T15

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

Listed price $649

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Niya Sonar

Niya Sonar 20

Above-ground pools up to 26 ft that need the floor cleaned without a cord.

Listed price $199

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A better alternative

What we recommend instead

Pool Express pick

Dolphin Escape

Inground and above-ground pools up to 30 ft that need floor cleaning.

$669

Buy Dolphin Escape

Buying guidance

Dolphin T15 or Niya Sonar 20: our take

Dolphin T15 and Niya Sonar 20 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

Both robots are intended for above-ground pools. Dolphin T15 is rated for pools up to 30 ft; Niya Sonar 20 is rated up to 26 ft. Each cleans floor, so coverage alone does not separate them. Dolphin T15 lists 1 active brush. Niya Sonar 20 lists Sonar navigation and Dual drive motors.

Filtration and debris

Both models include Basket.

Controls and day-to-day ownership

Both models provide one-touch starts and power-supply controls. Dolphin T15 uses a 40 ft corded cable, while Niya Sonar 20 uses cordless battery power. Dolphin T15 is listed at 14 lb versus 10 lb for Niya Sonar 20; that 4 lb difference matters when lifting the robot from the pool.

Price, warranty and the decision

Dolphin T15 is listed at $649 and Niya Sonar 20 at $199; Niya Sonar 20 is $450 less. Dolphin T15 lists a 2-year warranty compared with 1 years for Niya Sonar 20. Dolphin T15 and Niya Sonar 20 each have a specific fit, but neither is the Pool Express pick for this job. Our better alternative is Dolphin Escape. Inground and above-ground pools up to 30 ft that need floor 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 T15	Niya Sonar 20
Cleans the pool floor	Yes	Yes
Climbs and cleans walls	No	No
Scrubs the waterline	No	No
Fine-debris filter included	No	No
Large-debris filter	Yes	Yes
Automatic scheduling	No	No
Smartphone app	No	No
Anti-tangle swivel	Not listed	Not listed
3-year warranty	No	No
No recharging between cycles	YesEdge	No
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 T15 stands out

Dolphin T15 is the better fit for pools up to 30 ft.

Carries a 2-year warranty instead of 1 years
Is rated for pools up to 30 ft
Runs from continuous plug-in power without a recharge between cycles

Where Niya Sonar 20 stands out

Niya Sonar 20 is the better fit for shoppers prioritizing the lower $199 starting price.

Is listed $450 lower
Weighs 10 lb versus 14 lb