Best String Trimmer — Cordless, Gas or Corded, and Which One

For most suburban yards the best string trimmer is now a battery model in the 40V–60V class, with a 15–17 inch swath, 0.080 or 0.095 inch line and a head you can reload without taking it apart. That combination cuts as well as a consumer gas trimmer on ordinary grass and weeds, starts with a trigger, and needs no fuel mixing or carburettor work. Gas still earns its place on acre-plus properties, ditch banks and heavy overgrowth, where a tank of fuel outlasts any single battery. Corded trimmers remain the cheapest way to tidy a small lot within 100 feet of an outlet.

The decision that matters most is not the trimmer at all. It is the battery platform, because the pack you buy here will also run your blower, hedge trimmer and possibly your mower. Pick the platform first, then the trimmer within it. This guide covers seven proven models across all three power types and explains the specs that separate a good weed eater from a frustrating one.

The Picks at a Glance

The 7 Best String Trimmers

These are ranked for a typical homeowner with a quarter- to half-acre lot, some fence line, beds and a driveway to edge. Specifications are the manufacturers' published figures. Runtimes are manufacturer estimates and vary widely with grass density and speed setting.

Cordless vs Gas vs Corded

Cordless: Choosing the Platform

Battery trimmers have closed most of the gap with gas over the past several years, largely because of brushless motors and larger packs. For trimming grass and normal weeds around a typical suburban lot, a good 40V–60V cordless model is a match for a consumer 25cc gas trimmer. It is also quieter, lighter to start and almost maintenance-free. Most people should start here.

The voltage on the label is less meaningful than it looks, because brands quote it differently. Ryobi's and Greenworks' "40V" packs are 36V nominal. DeWalt's "60V MAX" is 54V nominal. EGO quotes 56V nominal. Milwaukee's M18 is 18V, and its FUEL trimmers make up for the lower voltage by drawing heavy current from large packs. The useful comparison is watt-hours, which is nominal voltage multiplied by amp-hours. That measures the energy the battery holds, and it is what determines runtime.

If you already have a platform for drills and drivers, the case for staying on it is strong, since batteries are the expensive part of any cordless tool. Our Milwaukee vs DeWalt comparison covers how those two platforms differ beyond the yard. Avoid the cheapest 18V–20V trimmers that use 0.065 inch line and 10–12 inch heads. They are fine for touching up a patio but tiresome on a real lawn.

Gas: Two-Stroke or Four-Stroke

Two-stroke trimmers like the Echo SRM-225 and GT-225 run on a fuel-oil mix (Echo specifies 50:1). They are the lightest gas option and offer the best power-to-weight ratio, which is why almost every professional crew uses them. The downsides are mixing fuel, exhaust smoke, noise, and carburettors that clog when ethanol fuel sits for weeks.

Four-stroke trimmers run on straight gasoline with separate crankcase oil, like a mower. They produce more torque at lower RPM, run quieter and smell less. The cost is weight, a higher price, oil changes and occasional valve adjustment. They suit someone who refuses to mix fuel and does not mind a heavier tool. Most homeowners who want to avoid mixing are better served by going cordless.

Corded

Corded electric trimmers are the cheapest, lightest and most reliable option. They also have no battery to wear out and replace. The cord is the limit. Beyond about 100 feet from an outlet, or on any lot with many beds and trees for it to snag on, the cord becomes the main source of frustration. For a small rectangular lot, though, a corded trimmer is an easy recommendation.

Straight vs Curved Shaft

Straight shafts are longer, reaching under shrubs, decks and fences and keeping the head further from your feet. They suit users of average or above-average height, rotate cleanly for edging, and are the basis of every attachment system. On gas models the straight shaft usually carries a drive cable or solid shaft to a gearbox at the head, which is more durable under heavy load.

Curved shafts are shorter and lighter, and they hold the head at a natural angle for shorter users. They are easier to manoeuvre in tight spaces and around obstacles. The flexible drive cable runs through the bend, so there is no gearbox at the head. The downsides are reach and edging, and curved shafts are rarely attachment-capable.

Nearly all cordless trimmers use straight shafts. One-piece models usually put the motor at the head, driving the line directly, while attachment-capable models keep the motor in the rear power head and drive the attachment through the shaft. Telescopic shafts, like the one on the EGO ST1511T, give a straight-shaft trimmer some of the curved shaft's adjustability for shorter users.

Cutting Swath and Line Diameter

Cutting swath is the diameter of the circle the line cuts. A wider swath, 16–17 inches, covers more ground per pass and is faster on open stretches, but it draws more power and shortens battery runtime. That is why several cordless trimmers let you shorten the line to a 13–15 inch setting. A narrower swath is easier to control around beds and fences. For most yards 15 inches is a good compromise, and 17 inches is worth having on large or rough properties.

Line diameter matters more than most buyers realise. Thicker line cuts tougher growth and lasts longer, but it needs more power to spin, so a trimmer's motor or engine determines how thick a line it can use.

Line shape also matters. Round line is the most durable and wears slowly against concrete and fences. Twisted and multi-sided (square, star) line has edges that cut more cleanly and aggressively through weeds, but it wears faster. Always use the diameter your trimmer's manual specifies. Line that is too thick overloads the motor and spools badly. Line that is too thin breaks constantly and cuts poorly.

Bump, Fixed and Auto Feed Heads

How a head lets out new line matters day to day, and reloading is the part of string trimming that people dislike most.

Bump feed is the standard. Tap the head on the ground while it spins and a centrifugal ratchet releases a short length of line, which the guard's blade trims to length. It is reliable and simple. The traditional nuisance is reloading, which used to mean opening the head and winding line onto the spool by hand. Modern heads remove most of that work. EGO's POWERLOAD winds line in at the push of a button, while Echo's Speed-Feed, Milwaukee's Easy Load and Ryobi's Reel Easy heads let you push a length of line through and wind it by twisting the knob, with no disassembly.

Fixed-line heads take pre-cut lengths of thick line, inserted one at a time. There is nothing to wind and nothing to jam, and they can use thicker line for brush. Replacing line takes longer each time, which suits heavy work better than routine weekly trimming.

Automatic feed, like BLACK+DECKER's AFS spool on the BESTA510, lets out line as it wears with no tapping. It is genuinely convenient on light trimmers. The usual caveat is that it uses thin line and can feed more than needed on hard surfaces, so expect to go through spools faster.

Attachment-Capable Systems

Split-shaft systems separate the power head from the working end, so one engine or motor can drive a trimmer, edger, pole saw, hedge trimmer, cultivator or brush cutter. DeWalt's 60V MAX trimmers, Milwaukee's QUIK-LOK, Ryobi's Expand-It and EGO's Multi-Head range all work this way, as do several gas families.

The appeal is that you pay for the motor and battery once. For a homeowner who needs occasional pole-saw reach for overhanging branches and a dedicated edger for a long driveway, a split-shaft system costs less and takes up less wall space than separate tools.

The trade-offs are weight and balance. The coupling adds mass at mid-shaft, and attachments built to fit many heads are rarely as well balanced as a dedicated tool. If you will only ever trim, a one-piece trimmer is lighter and simpler. If you know you want an edger and a pole saw, start with the system.

Runtime and Battery Size

Runtime depends on watt-hours, speed setting and what you are cutting. Battery trimmers draw far more on the high setting and in dense growth than on clean lawn edges, so a manufacturer's runtime figure is a best case rather than a typical one.

Those yard sizes assume typical edging around beds, trees and fences, run on the low or mid setting. A lot with long fence lines or heavy weeds uses more. The practical rule is that around 140–160 watt-hours covers a typical quarter- to half-acre lot. Beyond that, budget for a second battery or a larger one. A second battery also lets you finish the job while the first charges, which matters more than raw capacity if you trim in one long session.

Battery wear matters too. Lithium packs lose capacity with heat, deep discharges and age. Treat five to seven years as a reasonable expectation for a pack that is looked after, and price replacement packs before you commit to a platform. That cost recurs, and it is the one real running cost of a cordless trimmer.

Weight and Balance

Published weights mislead in two ways. Cordless figures are often quoted without the battery, which can add several pounds, and gas figures are often quoted dry, without fuel. Compare complete operating weights where you can.

Balance matters more than weight. A well-balanced trimmer pivots naturally at the rear handle with the head floating just above the ground, so your forearms are steering rather than holding up the head. Cordless trimmers with the motor at the head and the battery at the back balance quite differently from gas trimmers with the engine at the back. Adjust the front handle position until the trimmer hangs level. If a gas trimmer will be used for more than about 30 minutes at a time, a shoulder strap transfers the weight off your arms, and many gas trimmers include a strap or a mount for one.

Vibration adds to fatigue. Gas engines vibrate more than electric motors, and over a long session that causes more tiredness than a pound or two of extra weight. That is a real argument for cordless on large properties where you trim for an hour or more.

How to Edge With a Trimmer

A trimmer can produce a crisp edge along a driveway or path, which is often the single detail that makes a lawn look professionally maintained. It takes a little practice.

Turn the trimmer. Rotate the shaft so the head stands vertically, with the line spinning in a plane perpendicular to the ground. Straight shafts do this easily. On a curved shaft, the bend makes it awkward. Some trimmers, including the BESTA510, have a rotating head and a wheeled guide made for this.

Check the rotation. Most heads have an arrow showing which way the line spins. Hold the trimmer so the line throws debris away from you and onto the lawn or street rather than across the path, the car or your shins.

Go slowly and stay shallow. Hold the head at a steady height and walk at a steady pace with the line tip just entering the soil at the concrete's edge. Work in one continuous pass. Stopping and starting leaves notches. The first edge of the season takes longest, after which a monthly pass keeps it sharp.

Expect line wear. Edging along concrete wears line far faster than trimming grass. Round line lasts longer than twisted line here, and a dedicated edger attachment is worth considering on long driveways. Edging also pairs well with mowing on the same day. Our self-propelled mower guide covers the mowing side of a sharp-looking lawn.

For trimming along fences and around trees, tilt the head slightly so only the tip of the line touches the grass. The tip does the cutting, and burying more line than that just bogs down the motor. Around tree trunks, keep the line away from bark entirely. String trimmers girdle young trees surprisingly quickly, and a mulch ring is cheaper than a replacement tree.

Maintenance That Matters

All Trimmers

• Clean the head and guard after each use. Grass packed under the guard adds drag and can overheat cordless motors.
• Keep spare line on hand in the correct diameter. Line becomes brittle over the off-season, and soaking a spool in water overnight before reloading makes it more flexible.
• Check the line-cutting blade on the guard. A dull blade frays the line instead of cutting it cleanly.
• Inspect the head for wear. Worn eyelets cut line prematurely and are cheap to replace.

Gas Trimmers

• Use fresh fuel at the manufacturer's mix ratio, and add stabilizer if it will sit for more than a month. Ethanol-free premixed fuel costs more but is the simplest way to avoid carburettor problems.
• Clean the air filter regularly in dusty conditions, and replace the spark plug annually or per the manual.
• Grease the gearbox on straight-shaft models at the interval the manual specifies.
• Before winter storage, run the tank dry or use stabilized fuel, so old fuel does not gum up the carburettor.

Cordless Trimmers

• Store batteries indoors over winter at about half charge, not in a freezing shed or a hot garage.
• Let a hot battery cool before charging.
• Keep the motor vents clear of grass and dust.

A trimmer is also often the tool that applies weed control where it is needed most. Cutting weeds along fences before they seed reduces next year's crop considerably, and a trimmer cleans up where herbicide should not go, such as near vegetable beds.

The Short Version

For most yards under half an acre, buy a 40V–60V cordless trimmer with a 15–17 inch swath, 0.080–0.095 inch line and a head that reloads without disassembly. The EGO ST1511T is the easiest to live with. The DeWalt DCST972X1 is the best choice if you want attachments, and the Ryobi RY40290 offers the best value.

If you already own Milwaukee M18 batteries large enough to run it, the 3016-20ST is one of the most powerful cordless trimmers available.

For an acre or more, heavy weeds or brush, buy a 21–25cc two-stroke gas trimmer. The Echo SRM-225 is a long-standing benchmark, and the curved-shaft GT-225 suits shorter users. Owners of large properties may also be weighing a zero-turn mower, and a gas trimmer is the natural partner for one.

For a small lot near an outlet, a corded trimmer like the BLACK+DECKER BESTA510 does the job, and corded models as a class typically cost $50–$100.

Frequently Asked Questions

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