Robotic pool cleaner comparison

Dolphin S400 vs Niya Sonar 10

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 S400 and Niya Sonar 10 are compared feature by feature below. For a stronger Pool Express option, consider Dolphin Premier. Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris and heavy leaves.

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S-Line

Dolphin S400

Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.

Listed price $1,799

View better alternatives

Niya Sonar

Niya Sonar 10

Above-ground pools up to 20 ft that need the floor vacuumed without a cord.

Listed price $149

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A better alternative

What we recommend instead

Pool Express pick

Dolphin Premier

Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris and heavy leaves.

$1,999

Buy Dolphin Premier

Buying guidance

Dolphin S400 or Niya Sonar 10: our take

Dolphin S400 and Niya Sonar 10 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 S400 is intended for inground pools, while Niya Sonar 10 is intended for inground and above-ground pools. Dolphin S400 is rated for pools up to 50 ft; Niya Sonar 10 is rated up to 20 ft. Dolphin S400 cleans floor, walls, and waterline; Niya Sonar 10 cleans floor. Dolphin S400 lists 2 active brushes and CleverClean navigation. Niya Sonar 10 lists Dual drive motors.

Filtration and debris

Dolphin S400 includes Basket and UltraFilter; Niya Sonar 10 includes Basket. That gives Dolphin S400 the clearer documented edge for fine silt, pollen and sand.

Controls and day-to-day ownership

Dolphin S400 provides a weekly timer and smartphone control; Niya Sonar 10 provides one-touch starts and power-supply controls. Dolphin S400 uses a 60 ft corded cable with an anti-tangle swivel, while Niya Sonar 10 uses cordless battery power.

Price, warranty and the decision

Dolphin S400 is listed at $1,799 and Niya Sonar 10 at $149; Niya Sonar 10 is $1,650 less. Dolphin S400 lists a 2-year warranty compared with 1 years for Niya Sonar 10. Dolphin S400 and Niya Sonar 10 each have a specific fit, but neither is the Pool Express pick for this job. Our better alternative is Dolphin Premier. Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris and heavy leaves.

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 S400	Niya Sonar 10
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	Yes	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 S400 stands out

Dolphin S400 is the better fit for pools up to 50 ft.

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 Niya Sonar 10 stands out

Niya Sonar 10 is the better fit for shoppers prioritizing the lower $149 starting price.

Is listed $1,650 lower
Cleans the pool floor