Robotic pool cleaner comparison

Aquabot X4 vs Dolphin T55i

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

Aquabot X4 and Dolphin T55i are compared feature by feature below. For a stronger Pool Express option, consider Dolphin Quantum. Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.

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Aquabot

Aquabot X4

Inground and above-ground pools up to 60 ft that need floor, wall and waterline cleaning.

Listed price $747

View better alternatives

T-Line

Dolphin T55i

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

Listed price $1,699

View better alternatives

A better alternative

What we recommend instead

Pool Express pick

Dolphin Quantum

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

$1,649

Buy Dolphin Quantum

Buying guidance

Aquabot X4 or Dolphin T55i: our take

Aquabot X4 and Dolphin T55i 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

Aquabot X4 is intended for inground and above-ground pools, while Dolphin T55i is intended for inground pools. Aquabot X4 is rated for pools up to 60 ft; Dolphin T55i is rated up to 50 ft. Each cleans floor, walls, and waterline, so coverage alone does not separate them. Aquabot X4's documented cleaning system includes 1 active brush and Intelligent navigation.

Filtration and debris

Aquabot X4 includes Basket; Dolphin T55i includes Basket and UltraFilter. Dolphin T55i has the clearer documented edge for fine silt, pollen and sand.

Controls and day-to-day ownership

Aquabot X4 provides a weekly timer; Dolphin T55i provides a weekly timer, smartphone control, and included remote control. Both use a 60 ft corded cable with an anti-tangle swivel.

Price, warranty and the decision

Aquabot X4 is listed at $747 and Dolphin T55i at $1,699; Aquabot X4 is $952 less. Each lists a 2-year manufacturer warranty. Aquabot X4 and Dolphin T55i each have a specific fit, but neither is the Pool Express pick for this job. Our better alternative is Dolphin Quantum. Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.

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	Aquabot X4	Dolphin T55i
Cleans the pool floor	Yes	Yes
Climbs and cleans walls	Yes	Yes
Scrubs the waterline	Yes	Yes
Fine-debris filter included	No	YesEdge
Large-debris filter	Yes	Yes
Automatic scheduling	Yes	Yes
Smartphone app	Not listed	Yes
Anti-tangle swivel	Yes	Yes
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 Aquabot X4 stands out

Aquabot X4 is the better fit for shoppers prioritizing the lower $747 starting price.

Is rated for pools up to 60 ft
Is listed $952 lower

Where Dolphin T55i stands out

Dolphin T55i is the better fit for inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.

Includes filtration for sand, pollen and other fine debris
Has documented smartphone control