Segway Navimow X450 vs X350 Review (2026): $200 Buys 13° More Slope

Navimow X450 vs X350: side-by-side specs

Every figure below comes from Navimow's US store unless the row says otherwise. Where Navimow does not publish a number, the cell says so.

X350 or X450: which should you buy?

The number that decides this is the steepest grade on your lawn. Speed does not decide it, because Navimow's own figures put both mowers at the same daily coverage.

Navimow publishes the method on its X4 page. Daily coverage equals 24 hours divided by one mow-and-charge cycle, times the area covered per charge. We ran that formula for both models against a flat 1.5-acre lawn of 65,340 sq ft.

• X350: 200 min mowing + 80 min charging = 280 min per cycle. That is 5.14 cycles a day at 13,068 sq ft each, or 67,207 sq ft (1.54 acres).
• X450: about 110 min mowing + up to 90 min charging = 200 min per cycle. That is 7.2 cycles a day at 9,600 sq ft each, or 69,120 sq ft (1.59 acres).
• One full 1.5-acre pass: the X350 needs 5.0 charges and about 22.0 hours elapsed. The X450 needs 6.8 charges and about 21.5 hours.

Half an hour apart on a full pass is no reason to pay $200. Slope is the reason. The X350 is rated to 50% (27°) in the main lawn and only 25% (14°) at the boundary. The X450 is rated to 84% (40°). Navimow does not publish a separate boundary figure for the X450.

How to check your lawn before you buy. Lay a 4-foot level on the steepest strip, especially along fences, beds and driveways. Hold one end level and measure the drop to the ground at the other end.

• Drop of 12 inches or less: 25% grade or gentler. The X350 is inside its boundary rating.
• Drop above 12 inches at an edge: beyond the X350's 14° boundary rating. Buy the X450.
• Drop above 24 inches anywhere: beyond the X350's 27° main rating. Buy the X450.
• Drop above about 40 inches: beyond both ratings. Neither mower is rated for it.

What getting it wrong costs. Put an X350 on a lawn with a steep edge and it is working outside its rating on that strip. PCWorld's X350 tester saw the mower get stuck when AI-assisted mapping did not register that a slope was too steep. You then own a $2,799* mower and still trim that edge by hand every cut. On a lawn that passes the level test, the X450 buys you nothing the X350 does not already do, except a lower 0.75-inch cut and antenna-free setup.

Who the X450 is for, and who should skip it

Buy the X450 if:

• Your lawn is 1 to 1.5 acres. Navimow rates it for 1.5 acres and says map storage can reach 1.8 acres depending on layout.
• Any strip fails the level test above. The 40° rating is the whole reason this mower costs more than the X350.
• You cut warm-season grass low. The X450 goes down to 0.75 inch; the X350 stops at 2 inches.
• You want to skip siting a base station. That works only where Navimow Network RTK has coverage, so check your postcode on the X4 product page first.

Skip it if:

• Your lawn is under 1 acre. The Navimow X430 is the other variant on the same Navimow listing at $2,499*.
• Your lawn is flat and 1.5 acres or less. The X350 matches it on daily coverage for $200 less and runs quieter.
• Your lawn is over 1.5 acres. See our 1 to 2.5 acre roundup.
• You have a gate or path narrower than about 24 inches. That is the X4 body width Navimow lists.

What our X430 unit shows about X450 hardware

We have not had an X450 in hand. Our unit is the X430, which arrived on 2026-05-14 and was deployed on Rob's home lawn. Navimow sells the X430 and X450 as two variants of one product listing, and its battery listing names both models. The notes below are X430 observations, so read them as such.

• Setup: the X430 began cutting after its autonomous boundary walk. We did not site a base station or lay a perimeter wire.
• Slope: on a first-run pass along a sloped fence strip, the 4WD drive held traction without visible slip. We have not yet measured that strip's grade, so this is not a 40° verification.
• Still to publish: measured slope angle, noise level and cut quality. Full notes live in the X430 review.

Navimow X350: what you get for $200 less

Is it still sold? Yes. On 2026-09-13 navimow.com listed the X350 at $2,799* with an Add to cart button. Navimow still shows the X3 Series in its residential menu. It has not published a statement that the X450 replaces the X350. PCWorld reported a $3,499* retail price when it reviewed the X350 in July 2025. That is $700 above the navimow.com listing we checked.

Where the X350 is better. It runs 200 minutes per charge against about 110 on the X450, and it covers 0.3 acre per charge against 9,600 sq ft. It is rated at 60 dB(A) against under 68 dB(A). Navimow also lists Animal-Friendly Mode for more than 24 animal types, Alexa and Google Home control, IP66 protection, and three years of free 4G.

Where it falls short. The slope ratings are the gap: 27° in the main lawn and 14° at the boundary. It cuts 9.3 inches wide and no lower than 2 inches. Setup uses an RTK base station. Navimow says setup takes three steps within one hour, and PCWorld's tester had it running in 30 minutes. PCWorld also flagged that the mower "lacks a rain sensor," while Navimow's X350 page describes forecast-based weather pauses.

Pick the X350 if your lawn is 1 to 1.5 acres, passes the level test with every edge under a 12-inch drop, and you are fine with 2 inches as your lowest cut.

Navimow X450 and X350 FAQ