Model#: GWKN21142

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Greenworks 21142 10 Amp 18 in. Straight Shaft Electric String Trimmer / Edger

  • Greenworks 21142 10 Amp 18 in. Straight Shaft Electric String Trimmer / Edger
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The all electric operation of the Greenworks' line of tools provides not only reliable performance and dependability, but also offer a clean running alternative to gas powered tools as well. Each Greenworks' tool comes with a variety of performance and safety features that not only help you get the job done right, they also promise carbon emission free operation for a cleaner environment.Lightweight yet powerful, the Greenworks 21142 10 Amp Electric 18 in. Straight Shaft String Edge Trimmer has become known as the most powerful electric trimmer on the market. Boasting an 18 in. cutting path, the 21142 delivers the same great performance you'd expect from a gas trimmer in a lighter, eco-friendly design. Constructed with a durable straight shaft and comfortable molded grip for longer operation, the 21142 10 Amp Electric 18 in. Straight Shaft String Edge Trimmer delivers in both performance and reliability.
  • Powerful 10 Amp motor for reliable cutting power.
  • Wide 18 in. cutting path for tougher applications.
  • Quick-connect coupler allows for easy attachment changes and fits various name brands.
  • Lock-off switch helps prevent accidental start-ups.
  • Up to 25% lighter than traditional gas trimmers on the market.
  • Over-mold grips and handles for greater operator comfort.
  • 10 Amp 18 in. Straight Shaft Electric String Trimmer / Edger - 21142
Compliance and Restrictions
warning: Cancer and Reproductive Harm --


Length: 5.1 in.
Width: 13 in.
Height: 63 in.
Weight: 12 lbs.
Amperage: 10
Blade Construction: String
Bluetooth Compatibility: No
CSA Safety: Yes
Case Included: No
ETL Safety: No
Handle Type: Wrap Around
Motor Type: Brushed
Powered Tool Power Source: Electric - Corded
Starter Type: Electric
UL Safety: No
Voltage: 120V
Wifi compatibility: No



4.5 / 5.0
37 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Yes, I would recommend this to a friend (19)
No, I would not recommend this to a friend (1)
Powerful (18)
Lightweight (7)
Heavy (1)
No more pull cords to drive me insane
I purchased Greenworks 18-Inch 10 Amp Corded String Trimmer (Attachment Capable) 21142 just over a couple of months ago and congratulate myself every time I use it.The only drawback is that I also purchased the compatible replacement spool (29622) that doesn't fit (or even look like it fits).
August 11, 2018
Originally posted at
It took some time to learn how to handle this trimmer. You have to be careful bc of the power. The downside is it being corded, but that's why it is so powerful.
August 11, 2018
Originally posted at
Most powerful electric trimmer I've found
I was sick of messing with gummed up carbs from my trimmers sitting for long periods and my previous attempt with a corded trimmer left a lot to be desired, but after noting this was about 2x as powerful, I took a chance. Fantastic. Lighter than my gas powered trimmer, about as powerful, and takes all the old attachments. I was a little worried about using the edger attachment, but it worked just fine. After about 45 min of continuous use, there were no signs of overheating or anything which was my big concern. Can't recommend this enough - just take time to plan your route and the cord is a non-issue.
August 10, 2018
Originally posted at
When batteries just don't get it
Purchased this model to compete with gas trimmers and avoid charging batteries.
August 10, 2018
Originally posted at
Great lawn tool
I have had my trimmer over a year and find it is easy using convenient adjustment I can quickly use it for vertical edging on sidewalks and then horizontal near the foundation.
August 9, 2018
Originally posted at
Great trimmer from a great company
best string trimmer i have ever used.the first time i turned it on i krow i had all the power i would ever need.i have tall grass,but the best was the baby oak trees about 6 ins. went throught them like butter.
July 18, 2018
Originally posted at
First impression is positive
Plenty of power. Line is a little wimpy. May have to see what I can do to improve the diameter of the line. I have read on-line that string replacement can be challenging. I have not had it long enough to have to replenish the string. My main complaint is that the trimmer head rotates counterclockwise- so debris is thrown against my feet since I am right handed. If I could figure out how to make it rotate the opposite direction I would. That would be a big improvement. Other than that I am quite happy with it the 3 times I have used it so far. Check back with me at the end of the mowing season.
June 26, 2018
Originally posted at
Thrilled with this trimmer
I used my trimmer for the first time yesterday and was blown away by its quality. It is extremely well built and very balanced -- easy to hold. The power is terrific: loads of torque.

It's pleasant to see this level of quality at this price point.
June 13, 2018
Originally posted at
The Right Tool
As someone that use my ears for work, the 10 amp 18 inch corded string trimmer is quiet compared to a gas trimmer and for that I'm thankful.
April 30, 2018
Originally posted at
Powerful corded weed weedeater
So powerful it twists with torque in my hands. Power of a gas weedeater but quiet electric! Very happy!
April 29, 2018
Originally posted at

Questions & Answers

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Browse 15 questions Browse 15 questions and 10 answers
How do I replace the string?
Michael on May 9, 2017
replacement spool for greenworks model 21142 trimmer
Stef on Jul 29, 2016
BEST ANSWER: Greenworks 29622 Replacement Dual Line Spool for Model 21142. $9.99
I just bought a 21142 trimmer. Works great, but cord was used up quickly. What cord head can I order?

I tried SUN-31106524 at, but they don't list it.
What do I buy? Where?

Please help!
CJ on Jun 25, 2016
BEST ANSWER: Greenworks 29622 Replacement Dual Line Spool for Model 21142
will this work with try-bilt attachments?
E on Jun 8, 2016
BEST ANSWER: "Quick-connect coupler allows for easy attachment changes and fits various name brands."

The staff member who said you can't use attachments other than Greenworks didn't know what he was talking about. It will work with any standard attachment, so if the Troy-Bilt attachment uses the standard attachment then yes it will work.
What is the size of the bolt that goes on the trimmer head?
Nick7 on May 4, 2017
How do you reload the spool with line? I have seen videos that say there is a hole in the center of the spool but there isn't on mine.
Gnatalie on Mar 13, 2016
BEST ANSWER: For installation instructions, please refer to your manual or contact Greenworks directly at 866-577-3012
can a metal blade be attached to the trimmer?
A shopper on Feb 19, 2018
I have attacments for my gas powered weed eater Troy built and I know Craftsman will also interchange I have a rototiller hedge trimmer long chainsaw attachment will this work with them?
Gary S on Jul 27, 2019
BEST ANSWER: You will have to contact the manufacturer directly to check if the other brand will be compatible. the number to reach the technician is 1-888-908-6757.
How do you advance the string?
A shopper on Jun 22, 2017
BEST ANSWER: The same as any string trimmer. Tap the head on a hard surface.
I like mine.


Greenworks Warranty


When looking for lawn tools, we know you’re thinking about quality. You’re looking for something that will get the job done and get you back to your weekend. That’s why Greenworks backs tools with a four-year warranty (1 year on Pressure Washers) we know our products will perform at the highest level and always be reliable.


Greenworks products are protected against all defects under normal use for a period of four years (90 days for commercial use) from the shipping date. Pressure Washers carry a 1 year warranty.

Reconditioned GreenWorks products are protected against all defects under normal use for a period of 30 Days from the shipping date.

Greenworks can opt to repair, replace or issue a refund for products that are determined to be defective, or that have been damaged during shipping. Proof of purchase is required. Replacement of products or parts subject to normal wear and tear is the responsibility of the customer. If Greenworks accepts a return under Warranty, you can return the defective or damaged product only after you call and receive a Return Authorization from Greenworks. You also will receive a refund for your original shipping charges, and GreenWorks will arrange and pay for your return shipping charges. Lithium-ion batteries carry a two-year warranty against defects in workmanship and materials. Sealed Lead Acid batteries carry a one-year warranty against defects in workmanship and materials. Batteries must be charged in accordance with the operator’s manuals directions and regulations in order to be valid. See owners manual for warranty details.