Quick verdict
The cordless Dolphin for smaller pools and tighter budgets. You give up the 600's larger coverage and runtime, but keep the brand's reliability and a clean cordless experience.
Ideal for
- Smaller pools up to 33 ft
- Cordless buyers who want a proven brand
- Owners who value easy magnetic charging and retrieval
Not ideal for
- Large pools (get the Liberty 600)
- Surface-debris problems
- Longest-runtime chasers
The full picture
The Liberty 400 is the more affordable cordless Dolphin: floor, wall, waterline, and compatible sun-ledge coverage for pools up to 33 feet, a 2.5-hour cycle, interchangeable fine and ultra-fine filters, MyDolphin Plus app access (when the robot is out of the pool), Magnetic-Connect charging, Click-Up retrieval, and an Eco Mode. It brings Dolphin's brand confidence to the cordless category for smaller pools at a lower price than the Liberty 600.
Dolphin Liberty 400 at a glance
- Cleaning coverage
- Floor + walls + waterline
- Pool type
- In-ground and above-ground
- Max pool size (ft)
- 33
- Cordless
- Yes
- Wall climbing
- Yes
- Waterline cleaning
- Yes
- Filtration
- Interchangeable fine + ultra-fine
- App control
- Yes
- Weekly timer
- No
Source: Compiled from Maytronics product documentation, published specifications, and aggregated owner feedback.
This is a research-based review — our analysis draws on manufacturer specifications, manuals, warranty terms, and verified owner feedback rather than our own hands-on testing, and we note where a detail couldn't be confirmed. How we review
The in-depth review
The Liberty 400 is the cordless Dolphin for smaller pools — a step up from the 300, a step below the 600. You get floor, wall, and waterline cleaning with none of the cable, at a more approachable price than the top of the cordless range.
The cordless experience
No floating cable means you drop it in and lift it out, and Dolphin's Magnetic-Connect charging and Click-Up retrieval make the routine genuinely tidy — you set it on the base without fighting a plug and lift it out by the handle. Interchangeable fine and ultra-fine filters let you match the media to your debris, and it scrubs the waterline, which many cordless robots at this level skip.
Where it's capped
Coverage tops out at 33 feet, so this is a smaller-pool robot; for a big pool the Liberty 600 is the right call. There's no surface skimming, and the app works only when the robot is out of the water — it's for setup and settings, not in-pool control.
Performance breakdown
Research-based editorial judgments from specs, warranty terms, and verified owner feedback — not lab measurements. How we score
Pros and cons
What works
- Cordless Dolphin at a lower price
- Interchangeable fine/ultra-fine filters
- Magnetic-Connect charging and Click-Up retrieval
- Maytronics brand and service
What doesn't
- Smaller 33 ft coverage
- No surface skimming
- App works only when the robot is out of the water
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Frequently asked questions
Is the Dolphin Liberty 400 cordless or corded?
The Dolphin Liberty 400 is cordless — it runs on a rechargeable battery with no floating cable to manage.
What does the Dolphin Liberty 400 clean?
The Dolphin Liberty 400 is rated to clean the floor, walls and waterline. That includes the waterline, where sunscreen and body oils build into a greasy ring. It is an underwater cleaner, so it does not skim floating debris off the surface.
What size pool is the Dolphin Liberty 400 designed for?
It is rated for pools up to 33 feet. On a longer pool it covers less ground per cycle and can miss spots, so size up if your pool runs past that.
Does the Dolphin Liberty 400 have app control?
Yes — the Dolphin Liberty 400 pairs with a mobile app.
What filtration does the Dolphin Liberty 400 use?
It filters debris through an interchangeable fine and ultra-fine. Rinse it after each cycle so suction and pickup stay strong.
What warranty does the Dolphin Liberty 400 come with?
It comes with a 2–3 year manufacturer limited warranty — confirm current terms at purchase.