Comparison · 2 robots

HOBOT 388 Ultrasonic · HUTT DDC55

All robot window cleaners. Every measure below is plotted against the full class, so a difference can be read against how much the class itself varies.

HOBOT 388 Ultrasonic
HUTT DDC55

HOBOT

HOBOT 388 Ultrasonic

Autonomy: II Assisted Autonomy
Score: 70/100 Strong
Readiness: Ready Now
Price: $299list

HUTT

HUTT DDC55

Autonomy: II Assisted Autonomy
Score: 51/100 Limited
Readiness: Ready Now
Price: $279list

Up to three

01 Classification

What each one does on its own.

The Autonomy Ladder is the same five rungs for every robot on the site. A rung describes the conditions a robot handles without you, not how good it is.

Generalized

Any task, any setting

Environmental

Handles new obstacles without help

III

Conditional

Finishes familiar jobs on its own

Assisted

Runs preset routines, needs rescue

HOBOT 388 UltrasonicHUTT DDC55

Manual

One action, on command

02 Assessment

Where they actually differ.

The Robovations Score is nine inputs across three pillars, each weighted as shown and each scored so that more is better. A robot can lead on one and trail on another, which is the point of showing them apart. Cost of ownership and data handling are reported on each robot's own page and are never averaged into the score.

Capability

Task completion16% of score

Does it finish the job it is sold to do, unattended

7570

HOBOT 388 Ultrasonic75
HUTT DDC5570

18median 72 across 354 scored robots100

Coverage and navigation10% of score

Does it work the whole area, and hold that between runs

7055

HOBOT 388 Ultrasonic70
HUTT DDC5555

15median 70 across 344 scored robots100

Edge-case recovery10% of score

Does it recover from the failures its category presents

5050

HOBOT 388 Ultrasonic50
HUTT DDC5550

18median 50 across 261 scored robots100

Operating envelope4% of score

How far conditions can vary before performance drops

6575

HOBOT 388 Ultrasonic65
HUTT DDC5575

25median 70 across 320 scored robots100

Dependability

Field failure rate16% of score

Documented hardware failures per owner-year

8564

HOBOT 388 Ultrasonic85
HUTT DDC5564

6median 70 across 344 scored robots100

Software stability14% of score

Whether updates fix more than they break

3333

HOBOT 388 Ultrasonic33
HUTT DDC5533

15median 65 across 275 scored robots100

Support longevity10% of score

Committed parts, service and updates, with dates

7332

HOBOT 388 Ultrasonic73
HUTT DDC5532

0median 63 across 354 scored robots100

Ownership burden

Routine maintenance12% of score

Hands-on time it asks for in normal operation

3425

HOBOT 388 Ultrasonic34
HUTT DDC5525

22median 68 across 355 scored robots100

Consumables8% of score

Parts that must be bought to keep it working

9169

HOBOT 388 Ultrasonic91
HUTT DDC5569

30median 69 across 354 scored robots100

03 Measured against the class

How far apart is a long way?

A number only means something next to the spread it sits in. Each track below is the real range across every classified robot in the class, with the median marked.

Price19 with a published figure

$299$279

HOBOT 388 Ultrasonic$299
HUTT DDC55$279

$150median $365.80$850

Weight16 with a published figure

2 lbs2.5 lbs

HOBOT 388 Ultrasonic2 lbs
HUTT DDC552.5 lbs

1.3 lbsmedian 2.9 lbs4.8 lbs

Height15 with a published figure

3.7 in3.3 in

HOBOT 388 Ultrasonic3.7 in
HUTT DDC553.3 in

2.2 inmedian 3.5 in9.4 in

Not compared, because fewer than two of these robots carry a published figure: Suction, Runtime, Charge time, Noise.

04 Ownership

What the numbers leave out.

The trade-off

What each design gives up to be good at what it is good at.

HOBOT 388 Ultrasonic

Applying water as a mist rather than a soak keeps run-off off the sill, but a saturated pad on consecutive heavily-soiled panes still requires a mid-session swap that interrupts the automated workflow.

Coverage within a single pane is systematic and unattended; the unit cannot advance to the next pane without the owner relocating it and re-anchoring the rope.

HUTT DDC55

Entry-level cost buys fundamentals rather than features: the DDC55 holds the glass with a suction range HUTT states as 2000 to 3800 Pa and cleans with twin rotating discs, but it is a corded, remote-controlled machine with no app, no schedule and no mapping, and each pane is started by hand.

Who each one is wrong for

Stated by the record itself. A robot being wrong for a household is a fact about fit, not a fault.

HOBOT 388 Ultrasonic

Users expecting hands-free multi-window automation: Every pane requires manual placement, pad attachment, and safety rope anchoring. The unit automates the scrubbing path within a pane but does not eliminate per-window setup effort.
Homes with textured, frosted, or divided-pane glass: Surface irregularities break the suction seal. Owner reports confirm the unit detaches or loses path on patterned or divided glass, which is a safety risk in addition to a cleaning failure.
Buyers seeking a fully autonomous set-and-forget appliance: Window cleaners in this category require active supervision per session. The 388 automates path coverage within a pane, not the overall cleaning workflow across a home.
Owners with small standard windows cleaned rarely: Manual squeegee effort on small panes is often faster than the 388 setup cycle. The time-savings case is strongest on large or difficult-to-reach glass.

HUTT DDC55

Windows with no immovable anchor point for the safety rope: HUTT's procedure requires the safety rope's locking ring to be fixed to a solid object that cannot be dragged, and requires the rope to be checked before every run for secure attachment and damage. Where a window offers no such anchor within reach, the machine should not be run on it.
Hard-water areas or homes with frequently soiled panes: The cloths are wetted by hand before a run and the machine carries no water of its own, so mineral deposits and heavy pollen mean pre-treating the pane and changing the cloth part way through.
Owners needing app control, scheduling or mapping: The DDC55 is driven from a handheld remote. There is no network connection, no app and no schedule, and the machine has to be placed on each pane by hand before it will run.

What stays your job

The upkeep ownership hands back to you, whatever the autonomy level says.

HOBOT 388 Ultrasonic

After every use: Remove microfiber pad, rinse with water, and hang to dry before storage.
After every use: Wipe suction ring with a clean damp cloth to remove glass cleaner residue that degrades the seal over time.
Monthly: Inspect safety rope for fraying; replace if any strand damage is visible before next use.
Every 3-6 months: Clean suction motor intake port with a dry brush to remove dust accumulation that reduces grip force.
Every 3-6 months: Check pad contact surface on the cleaning head for mineral buildup; rinse with diluted white vinegar if present.
Annually: Inspect power cable and connector for sheath cracking; manufacturer recommends replacement if outer jacket is compromised.

HUTT DDC55

Before every run: Check that the safety rope is undamaged and that its locking ring is fixed to a solid object that cannot be dragged.
After every use: Remove the cleaning cloths from the turning discs, rinse them and let them dry before the next run.
Weekly: Inspect the cloths for loose threads, tears or embedded grit and replace worn cloths.
Bi-weekly: Clean the vacuum intake and motor filter with a soft brush, especially in dusty environments.
Monthly: Inspect the power cable, adapter and extension lead for insulation damage, and confirm the extension lead’s locking knob is tight.
Seasonally: Before extended storage, dry all components and store the cable loosely indoors to prevent moisture damage.

05 Evidence

How much each of these is standing on.

Classifications rest on different depths of evidence. A pre-release assessment and a verified one are not the same kind of claim.

Evidence behind each classification
Robot	Evidence status	Sources reviewed	Last assessed
HOBOT 388 Ultrasonic	Verified	9	Aug 2026
HUTT DDC55	Pending	1	Aug 2026