Liectroux G9 vs G8: Which Window Cleaning Robot Should You Buy?

If you have a home with huge windows or live in an apartment with a lot of glass, cleaning the windows is a tedious task. Liectroux offers two window cleaning robots well worth considering: the G9 and the G8.

The Liectroux G9 is built for stubborn dirt: it uses dual motorized arms that actively scrub like human hands, paired with 10,000Pa suction (roughly three times stronger than typical competitors).

The Liectroux G8 prioritizes speed and practicality: lightweight at 1.16kg, ultra-thin at 72mm, and capable of cleaning a large window in minutes.

Let’s see how these two window cleaning robots compare.

Liectroux G9 vs G8: Quick Specs

Cleaning Performance and Suction Power: G9 vs G8

Understanding the Suction Difference

The G9 delivers 10,000Pa of suction force. The G8 delivers 3,000Pa. That’s a 3:1 ratio—the G9 pulls three times harder. Even when compared with popular competing products on the market—including the Ecovacs W2S PLUS with 10,000 Pa of suction, the HUTT S7 with 5,500 Pa of suction, and various models in the HOBOT lineup, the Liectroux G9 still stands out for its outstanding suction performance.

Suction force keeps the robot glued to the window. Too little suction, especially on a high-rise on a windy day, and the robot slides or falls. Too much, and it’s overkill for daily maintenance.

If you live on floors 1–5, clean regularly in calm weather, and your windows don’t have stubborn mineral deposits, the G8’s 3,000Pa is perfectly safe. If you’re on the 15th floor, deal with coastal wind, or have hard water stains that’ve built up over months, the G9’s extra suction capacity gives you peace of mind.

The Two Cleaning Approaches

G9’s dual-arm system: The robot has two motorized arms that move side-to-side at controlled pressure, mimicking human hand scrubbing. This works exceptionally well on: dried water stains and mineral deposits, bird droppings that have hardened, months-old grime buildup, textured glass surfaces.

G8’s high-speed disc system: Two counter-rotating discs spin at 40 RPM with 55N downforce, simulating manual side-to-side wiping. It excels at: quick maintenance cleaning every 1–2 weeks, light dust and rain spots, fast coverage across multiple windows, gentle cleaning on delicate surfaces.

The G8 can cover a large window in 3–5 minutes. The G9 takes longer but achieves deeper dirt removal.

Navigation, Edge Detection, and Spray Modes

How Each Robot Plans Its Path

Both robots automatically detect window dimensions and choose optimal paths. Neither requires manual pre-programming.

The Liectroux G9 offers 9 cleaning modes, including Auto Mode that intelligently selects Z-pattern or N-pattern based on glass width. If the window is wider than 70cm, it defaults to Z-pattern (back-and-forth rows). If narrower, it switches to N-pattern (diagonal coverage). You can press one button and let the robot decide the best approach.

The Liectroux G8 has 5 focused modes, including dedicated left-edge, right-edge, and edge-following modes. These are simpler to navigate, each targeting a specific frame or corner. No mode confusion, no decision paralysis.

Edge and Corner Cleaning—Critical for Framing

Windows aren’t just flat glass; they have frames, corners, and edges where dirt accumulates.

The Liectroux G9 can use 4 rotating corner brushes spinning at 200 RPM to reach into corners and along frames. The combination of the motorized arms (for general surface cleaning) plus these rotating brushes provides aggressive edge coverage. The G8 features 4-edge bionic silicone wiper strips with ~99% edge coverage. It doesn’t have rotating brushes, but the silicone strips conform to corners and frames well.

If your window frames are dirty or dusty, the G9’s rotating brushes will deep-clean them noticeably better. If you’re doing light weekly maintenance, both handle edges adequately, and the G8’s dedicated edge modes just give you more granular control.

Spray Systems: Wider Coverage vs More Water‑efficient

The Liectroux G9 features an industry‑first 8‑nozzle high‑pressure spray matrix combined with intelligent pulse‑pump technology. This system delivers uniform, continuous water coverage that quickly softens and dissolves stubborn glass stains. With support for both manual and automatic spray control (these are counted among the G9’s 9 cleaning modes), the G9 adapts to different cleaning scenarios — from light dust to heavy grime. The 120ml tank is shared with the G8, but the G9’s eight nozzles cover a wider area per pass.

The G8 employs a 2‑nozzle micron‑level pulsed atomisation system that sprays a fine, even mist every 3 seconds. This approach matches water output to glass dirtiness, ensuring the surface is wiped clean and dries quickly without water marks. The 120ml tank supports up to 6,000 sprays, covering approximately 30 square metres per fill.

Starting Up the Robot: Key Operational Differences

Liectroux G9 — Direct Start from Any Device

You can start the G9 using any of three methods: the mobile app, the 2.4GHz remote control, or the button on the robot body. All three give you the same one‑touch start capability.

In addition, the G9 includes built-in AI voice prompts that announce: Mode changes, Cleaning progress, Completion status, Any error conditions. This is valuable for high-rise cleaning where you can’t always see what the robot is doing. The voice feedback gives you real-time confidence that the robot is operating normally.

Liectroux G8 — Step‑by‑Step Start‑Up

The G8 requires a specific sequence: 1. Flip the power switch on the robot’s bottom. 2. Press the power button on the body. 3. Place it on the glass and wait for suction to engage. 4. Now use the app or remote to select a mode.

If you prefer to start directly from the body, long‑press the button to start, place the robot on the window, and after it attaches, short‑press the button again — the robot will then default to Z‑pattern mode for the entire pane.

The G8 provides feedback via app notifications and visual indicators on the unit only.

Price, Coupons, and Which Model to Buy for Your Use Case

Pricing & Coupons on Banggood

Apply the coupon code at checkout to receive the discounted price.

Buying Decisions by Scenario

Get the G9 if: You live on the 10th floor or above; Your windows have months of grime, hard water stains, or mineral deposits; You experience regular wind and want maximum safety margin; You value wireless convenience and instant start-up; You want audible feedback during operation.

Get the G8 if: You clean windows every 1–2 weeks; You live on lower floors in stable weather; You need lightweight, easy-to-store equipment; You prefer simple, straightforward operation; Your windows mostly need dust and rain spot removal.

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