The Best String Trimmers of 2021

Cut back unruly growth and trim landscaping edges and borders with this handy outdoor power tool.

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The Best String Trimmer Option

Photo: amazon.com

Mowing the lawn spruces up a yard, but it’s the finishing touches that take a lawn from fine to fantastic—and there are spaces that a mower just can’t reach. That’s where string trimmers (also called weed eaters or weed whackers) make a difference. They fit into those spots around driveways, lawn ornaments, tree bases, and playground equipment without issue, helping give your lawn that professional look.

String trimmers use a quick rotation to whip off the top of grass and weeds. Selecting the best trimmer for your yard makes adding the finishing touches to the lawn an easy-to-complete task. Below are some of the best string trimmers on the market and some of the most important characteristics for you to consider while shopping.

  1. BEST OVERALL: BLACK+DECKER LSTE525 Lithium Easy Feed String Trimmer
  2. BEST BANG FOR THE BUCK: Greenworks 13-Inch 4 Amp Electric Corded Trimmer
  3. BEST GAS MODEL: Remington RM25C 25cc 16-Inch Gas String Trimmer
  4. BEST LIGHTWEIGHT: BLACK+DECKER String Trimmer with Auto Feed
  5. BEST FOR BEGINNERS: WORX WG163 PowerShare 12″ Cordless Trimmer & Edger
The Best String Trimmer Option

Photo: amazon.com

What to Consider When Choosing the Best String Trimmer 

Knowing what attributes to look for in a string trimmer helps in the search. Whether it’s the type, weight, ergonomic considerations, or attachment versatility, some features may provide a greater benefit than others for each situation. These considerations can help reveal which string trimmer is the best string trimmer for each user’s situation.

Type

String trimmers are classified as either corded or cordless:

  • Corded trimmers require an extension cord and a power outlet. They provide an unlimited power source and don’t require refueling or battery replacement.
    Cordless trimmers are either gas- or battery-powered, giving the user freedom to use the trimmer anywhere in the yard.

String trimmers also can be grouped depending on whether they are corded electric, battery-powered, or gas-powered:

  • Corded electric trimmers are lightweight and turn on with a switch. This type is reliable for small yards with an accessible outlet where the cord can reach all areas of the lawn to ensure a complete job. Low maintenance and reliable power are these trimmers’ strongest features.
  • Battery-powered trimmers are more maneuverable than corded trimmers. These turn on with a switch and are a handy choice for low-maintenance lawns. Depending on lawn size, a backup battery may be needed to finish a job.
  • Gas-powered trimmers are more robust, best for tougher jobs because they offer more power than electric string trimmers. These trimmers may require a mix of gas and oil to operate and occasional maintenance. Most models have a pull-start.

Cutting Width 

Cutting width, or cutting swath, is the diameter of the trimmer. Choosing the right width helps users get trimming done quickly and efficiently. For an increased cutting swath, choose a trimmer with a long line rather than manually overextending the line length during use. Overextending the line length for a larger cutting width reduces the efficiency of the trimmer, as the engine has to spin more weight than its design intended. To get the job done faster, string trimmers with dual heads can cut more efficiently than single-string trimmers.

The type of string used in each trimmer contributes to how efficiently the trimmer cuts down the grass, weeds, or overgrown areas. The thinnest line is 0.065 of an inch; it’s used for lighter-duty work, generally with smaller cordless or electric trimmers. A thicker line of 0.08- or 0.095-inch is more durable and increases cutting power.

Variable Speed Control

Some trimmers have variable speed controls for different cutting conditions. On battery-powered models, there may be two speed controls—one to increase the power for use on thicker/overgrown areas and the other to lessen power to trim perimeters while extending battery life. Gas-powered trimmers may use a throttle response for quick-powered adjustments when tough weeds or thick growth need tending.

Routine home maintenance doesn’t require professional landscaper tools. Many affordable trimmers lack speed control, offering one consistent speed for all conditions. One speed optimizes the length of time a string trimmer can be used without needing to change a battery or refuel.

Feeding and Loading 

The string trimmer’s spool supports a single or double line, depending on the style of the trimmer. A single line loads by winding the string around the spool and feeding it through the feed hole. Double-line heads require users to separately wind two lines of string around the spool so they don’t get tangled.

There are a few methods for feeding the string into the trimmer, depending on the model.

  • Manual feed is not common, but it’s a handy backup option. Users need to turn off the trimmer and follow the manufacturer’s instructions for pulling out the line by hand.
  • Bump feed requires the user to tap the bottom of the trimmer on the ground to release more line.
  • Push-button feed sends more line through by using a button on the handle.
    Automatic feed senses when the string is too short and lengthens it without any action from the user.

When loading the trimmer with a new string, use the correct line size. A heavier string puts extra stress on the engine and may affect overall performance.

Ease of Use 

How long it takes to trim the edges of a lawn depends on the size of the lawn and can be anywhere from a few minutes to longer than a half-hour. Some features of lawn trimmers that make them easier to use include ergonomic design, weight, tilting head, and balance.

  • Ergonomic design reduces unnecessary strain on the user. A telescopic shaft prevents hunching over, and adjustable handles personalize the trimmer to the user’s size to prevent holding it in an uncomfortable position.
  • Lightweight models are easier to use for longer periods. The weight of more powerful, heavier machines may prompt taking breaks to relieve muscles, making the job take longer than expected.
  • Tilting heads can go into areas where the operator doesn’t have to contort or maneuver their body.
  • Balance makes using a trimmer comfortable for longer periods. A straight trimmer shaft helps provide better weight balance, making it more comfortable to hold.

Noise and Vibration

Noise is not much of an issue with electric string trimmers. Typically the whirring sound of the string and the cutting sound are the loudest components. These types of trimmers don’t usually require hearing protection, as they are very quiet compared to their gas-powered counterparts. Gas trimmers, and some electric models, require hearing protection. These kinds are more robust and require additional juice to tackle tougher outdoor jobs.

As the engine works to make the lines rotate, it causes vibrations that can contribute to user fatigue. Many new string-trimmer models use handles with a flexible material that absorbs some of the vibrations, reducing the intensity transferred to the operator. Wearing heavy-duty gloves when using the trimmer also can help minimize blisters caused by those vibrations.

Attachments

Many string trimmers convert to an edge trimmer with a couple of quick adjustments. Some models also work with other attachments, using the same engine but swapping out the tool’s head. String trimmers that use attachments go by many names, including “multifunction” or “multitool.” To get the benefit of attachments, users need to purchase a trimmer specifically intended for multiple purposes.

Some of the attachment heads available may include the following:

  • A leaf blower spins a blower fan for quick cleanup.
  • An edger helps tidy lines around the driveway or walkway.
  • A cultivator stirs top layers of soil or helps remove and control weeds.
  • A brush cutter trims thicker growth or small saplings.
  • A pole saw cuts through tree limbs up to 9 inches thick.
  • A hedge trimmer readily trims hedges at the same time as trimming the grass.

Safety Features 

As a power tool, the string trimmer has the potential to cause injury. This device rotates at high speeds to cut down grass or weeds but can also throw debris, including rocks. Most trimmers have safety features in place to reduce the likelihood of accidents. Some of these safety features include:

  • Safety guards on the side of the trimmer closest to the operator. These guards deflect objects away from the user to minimize the risk of injury. Always make sure the guard is in place when the trimmer is in use.
  • Safety locks for height and handle adjustments to ensure the string trimmer doesn’t move unexpectedly during operation.
  • Safety switches for the quick shutdown of the tool.

In addition to the safeguards in place from the trimmer, users should also wear the appropriate personal protective equipment (PPE), including protective glasses, closed-toe shoes, long pants, and hearing protection (if warranted).

Our Top Picks

The string trimmers below were chosen based on the size, weight, fuel type, safety features, and overall performance, with a further emphasis on the other important factors mentioned above. These are among the best string trimmer tools for keeping the yard and garden maintained and manicured.

Best Overall

The Best String Trimmer Option: BLACK+DECKER LSTE525 Lithium Easy Feed String Trimmer
Photo: amazon.com

This battery-operated string trimmer from BLACK+DECKER simplifies edging and trimming, a valuable benefit with lawn care. A cutting swath of 12 inches gives users enough diameter to tackle lawn edges and areas around landscape features and flower beds.

The string trimmer uses two-speed control so users can boost the power for any stubborn brush. A push of a button automatically advances the spool for simplified feeding; no bumping or manual work is required. This model has an adjustable height and adjustable handle with a premium micro-texture soft grip, enabling users to customize the settings for an ergonomically comfortable fit.

The 6-pound string trimmer is lightweight enough to carry around until the job is done. This model comes with two 20-volt batteries and a charger. The batteries work with other BLACK+DECKER products and can be swapped out for a larger battery if desired.

Pros

  • Cord-free operation
  • Customizable and ergonomic design
  • Two speed settings
  • Converts from string trimmer to wheeled edger

Cons

  • Limited run time, even used on lower power


Best Bang for the Buck

The Best String Trimmer Option: Greenworks 13-Inch 4 Amp Electric Corded Trimmer
Photo: amazon.com

This Greenworks string trimmer provides the unlimited run time of corded electric power, so there’s no need to stop and change a battery or refill gas. The 13-inch cutting width and dual-line head slice down the brush and clean the lawn edge swiftly. Weighing only 7 pounds and offering a customizable height from the telescoping pole, this string trimmer works well for taller users. Since it’s electric, the sound is minimal.

When strings wear down, push the trigger button and the strings automatically advance to the line cutter. When it’s time to reload the string, use a 0.065-inch monofilament string and ensure that both sides of the spool are wound for dual-sided use.

Created for smaller yards, it requires the use of an outdoor polarized extension cord. The design incorporates a strain relief hook in the handle for the extension cord so it doesn’t accidentally disconnect when in use.

Pros

  • Unlimited run time
  • Customizable shaft size
  • Quiet operation

Cons

  • Limited by the length of the cord(s)


Best Gas Model

The Best String Trimmer Option: Remington RM25C 25cc 16-Inch Gas String Trimmer
Photo: amazon.com

Remington’s gas-powered string trimmer not only takes on stubborn weeds easily, but it also works in areas requiring a gentle touch. Using a gas engine, this model gives strength and control when thick patches of growth need cutting down. A 16-inch cutting width and dual-string head trim more area in less time than heads with smaller cutting swaths and single strings.

The two-stroke engine may be a bit loud, but it’s easily rectified with suitable hearing protection. This string trimmer uses a thick 0.095-inch twisted line with a bump-head design, so users need to tap the head on the ground and squeeze the trigger to feed additional line.

Its quick-start technology helps reduce the pain points common with starting traditional gas trimmers. The ergonomically curved shaft makes trimming edges and hard-to-reach areas gentler on the body—a welcome benefit when there’s a big job to do.

Pros

  • Larger, 16-inch cutting swath
  • Thicker string for tougher cuts
  • Ergonomic design
  • Gas power but with quick-start technology

Cons

  • Louder operation


Best Lightweight

The Best String Trimmer Option: BLACK+DECKER String Trimmer with Auto Feed
Photo: amazon.com

This BLACK+DECKER corded electric string trimmer weighs approximately 3 pounds, reducing the strain that comes with this chore. At 6.5 amps, the trimmer can handle a small to midsize backyard with an extension cord. It has the safety feature of a cord-retention system to prevent disconnection from the power source while working.

Though lightweight, its cutting swath is a convenient 14 inches, tackling the same area as heavier models. A speed of 8,000 rpm gives this little trimmer the force to quickly take down growth. No bumping is necessary when feeding the 0.065-inch-thick line; this string trimmer uses an automatic feed to keep the string at the right length. The shaft adjusts to fit most user heights and reaches into many areas. Lightweight and well-balanced, this trimmer is easy and comfortable to use for trimming and edging.

Pros

  • Easy to carry
  • Middle-of-the-road 14-inch cutting swath
  • Converts from string trimmer to wheeled edger

Cons

  • Limited by the length of the cord(s)


Best for Beginners

The Best String Trimmer Option: WORX WG163 PowerShare 12 Cordless Trimmer & Edger
Photo: amazon.com

One size fits many with this battery-powered string trimmer and edger from WORX. At less than 6 pounds, it’s light enough to carry around the yard and sturdy enough to take down difficult weeds. An adjustable handle ensures a comfortable grip, reducing unnecessary strain and awkward hold.

The 90-degree pivoting head on this WORX model helps users trim areas that are inaccessible or uncomfortable for locked-head trimmers. This head tilt comes in handy for sloped terrain and areas that are harder to reach, such as under a backyard playground. The two 20-volt batteries provide enough juice to trim an average-size yard with power to spare. A 12-inch cutting diameter and 0.065-inch line handles most yard jobs. This device comes with an adjustable spacer guard that extends to protect flowers, plants, and other features from accidentally getting cut.

Pros

  • Pivoting head provides increased reach
  • Spacer guard protects plants
  • Cord-free operation

Cons

  • Small spool size requires frequent changes


Our Verdict

Unencumbered by cords, the battery-powered BLACK+DECKER LSTE525 string trimmer is our top recommendation for users with small to medium yards because of its light weight (only 6 pounds!) and easy maneuverability. Those attending to larger properties or stronger weeds should invest in something a bit more heavy-duty like the Remington string trimmer boasts a 25cc gas engine and a 16-inch, dual-string cutting swath.

How We Chose the Best String Trimmers

String trimmers range in type and features, some of the most important considerations being your specific yard but also the cutting coverage, power, and ergonomic design of the model. These recommendations for the best string trimmers all have cutting width between 12 to 16 inches and variable power settings to allow users the option to tackle long runs and target increased power on difficult terrain. Many even have customizable height options so that users don’t overextend themselves and, outside of one with a gas engine, they all weigh between 3 and 7 pounds.

The power source is not to be overlooked, either. In this roundup, you’ll notice only one gas-powered recommendation for more heavy-duty landscaping needs. While they may be better suited for large yards with dense weed growth, more neighborhoods and cities are adopting regulations around the noise and air pollution associated with gas engines. For these reasons, the rest of our top picks are electric. Corded trimmers are a good choice for small- to medium yards if you don’t mind the extension cord, and cordless trimmers allow users to cover slightly larger properties without worrying about where the nearest electrical outlet is located. When recommending battery-powered options, we focused on ones that have at least one extra battery to always have a spare on the charger.

FAQs

Before putting on safety gear and heading out to use a new string trimmer, you may have a few lingering questions. Here are answers to some of the most frequently asked questions about string trimmers to help you get started.

Q: How does a string trimmer work?

The string trimmer’s engine rotates fast enough that the lines of string at the base whip around with the force required to cut down grass, weeds, and other growth.

Q: What do I use a string trimmer for?

For areas that a lawn mower can’t reach or cut properly, such as around a mailbox or tree base, a string trimmer efficiently targets and cuts down growth. It cuts problematic areas, but some stubborn patches may require weed killer, crabgrass killer, or other weed and feed products.

Q: Are string trimmers dangerous?

Trimmers can be dangerous since they fling debris at high rotations per minute (rpm), which is why proper safety features are built into the designs, and PPE should be worn when operating a string trimmer.

Q: How long do string trimmers last?

String trimmers last many years with proper care. Replace the line when it runs out, charge the batteries when needed, and do routine maintenance on gas trimmers to ensure longevity.