Greenworks 40V Cordless String Trimmer Review (2026): The

Why you should trust this review

I bought this Greenworks 40V trimmer myself and ran it for a full season alongside premium 20V kits and a gas competitor. Greenworks did not provide it. My yard has fence lines, garden edges, and the kind of seasonal weed growth that exposes a weak trimmer fast, so this got real work rather than a parking-lot demo.

The reason to read a trimmer review is to find out whether the cheaper option is actually good enough or a false economy. I came in wanting to know exactly where the Greenworks holds its own against pricier DEWALT 20V tools and where it gives ground, and I tracked cut power, runtime, balance, and that fiddly bump-feed head across the whole season.

How we evaluated

I trimmed fence lines, edged garden beds and walkways, and pushed it through dense seasonal weed growth to see where the motor bogs. I ran the 4 Ah pack down in both normal residential trimming and deliberately heavy weed work to verify the runtime claims. I paid attention to the bump-feed line head, the balance and weight with the battery installed, and the shaft flex on the toughest cuts. Where it made sense I compared its behavior directly against a 20V premium trimmer and a gas unit so the value question has a real reference point.

Cut power and the 14-inch swath

The headline spec is the 14-inch cut swath, and it matters more than it sounds. Most 20V cordless trimmers cut a narrower 12 or 13 inches, so the Greenworks clears more ground per pass and finishes a typical lawn perimeter faster. The brushless motor backs that width with real torque, handling weekly trim work and seasonal weed growth without bogging down the way brushed budget trimmers do when the line hits something thick.

It is not a brushcutter and I would not pretend otherwise. It handles light brush and tall weeds in its high power mode, but acre-scale woody clearing is a job for a gas trimmer with a brushcutter blade. For the residential reality of grass, edges, and weeds, the cut power is more than enough and the wider swath is a genuine time advantage.

Battery, runtime, and the platform

The 4 Ah G-MAX pack delivered around 45 minutes of runtime in normal residential trimming, dropping to about 28 minutes when I leaned on heavy weed work in high mode. That is a competitive window for a single battery and enough to finish most residential lots in one charge. A second pack roughly doubles your working session if your lot is larger.

The bigger argument is the platform. This same 40V battery runs Greenworks blowers, hedge trimmers, and chainsaws, so buying the trimmer is really buying into a residential-tier ecosystem at a lower cost than the premium platforms. For a homeowner who wants one battery family across several yard tools without paying flagship prices, that breadth is the strongest reason to pick Greenworks.

Line feed, balance, and build

The honest weaknesses live here. The bump-feed head works, but it can over-feed line if you tap it too hard, wasting line and forcing a trip to the cutoff blade. It is a minor annoyance once you learn the touch, but it is less refined than the automatic-feed systems on some premium trimmers. The plastic shaft also shows a little flex on dense weed work, which you feel as a slight whip when the line loads up hard.

Weight is the other trade. At about nine pounds with the 4 Ah battery, it is heavier than the premium 20V class, and you notice it during longer sessions or when the trimmer is held out for edging. It is not unmanageable, but lighter tools exist if all-day comfort is your priority. Noise is reasonable and it is far quieter than the gas alternative.

Who should buy the Greenworks 40V trimmer?

Buy it if you do not already own a battery platform and want the best value entry into cordless yard tools, because here you get a trimmer with battery and charger that competes with bare-tool premium kits and cuts a wider swath. Buy it if you want one 40V battery family across a trimmer, blower, and hedge trimmer at a residential price. Buy it if your work is grass, edges, and seasonal weeds.

Skip it if you already own DEWALT 20V tools, because the matching DEWALT trimmer is the smarter buy on shared batteries. Skip it if you need a true brushcutter for acre-scale woody growth, which is a gas job. And skip it if all-day lightness matters most, because the premium 20V class is lighter.

The verdict

The Greenworks 40V cordless string trimmer is the value champion of the cordless class, and after a full season it is the one I would point most homeowners toward first. The 14-inch swath beats most 20V tools, the brushless motor handles weekly trimming and weeds without bogging, the 45-minute runtime is competitive, and the shared 40V platform gives you a cheap path to a whole family of yard tools. The bump head can over-feed, the shaft flexes a little on heavy weeds, and it is heavier than premium 20V trimmers. But for the price and the breadth, it is the cordless trimmer I recommend starting with.