The 10 Best String Trimmer Heads of 2026

Genuine parts have one advantage no universal head can match: the thread is the one Echo cut on the shaft. The Speed Feed 400 threads straight onto SRM and PAS straight-shaft trimmers with a single tool and no adapter stack, so there's no bushing to lose and nothing to assemble in the wrong order. At 10.6 ounces it's lighter than most of the universal heads here, which matters at the end of a long fence line.

We keep this one for the Echo in the shed that should feel factory-original. It screws on in minutes, the bump action is the one the machine was designed around, and it makes an older SRM cut like a sharp knife again. The catch is that it ships with no adapters at all, and Echo has used more than one arbor thread across the SRM line — a 10 by 1.25 mm shaft is the common case, but the older 8 mm models take a different head. Check yours before you order.

It's a plastic-bodied head, and rocky ground and constant concrete edging are where it gives up first. On lawn, fence line, and pasture edge it does exactly what a factory head should, and it never asks you to keep track of five different nuts.

There's no spool inside the EZ Lock, and that is the entire point. You cut line into fixed strips, feed four of them through the eyelets, and twist the collar — no winding, no bumping, no birds' nests. The EZ Lock is the weed eater head for anyone who has stood in the yard fighting a tangled spool, because the reload takes seconds and you can do it with gloves on.

The trade is real: you stop and swap strips instead of tapping out more line, and thick wiry grass eats a strip faster than a spool would. What you get back is cutting force — four lines instead of two, a 6.44-inch swath, and enough bite for fence rows and big weeds.

The mount threads on with the included hardware, and the cordless fit list is unusually specific: Craftsman 20V, Hart 20V and 40V, DeWalt 20V through 60V, Echo 56V and 58V, Milwaukee 18V, Ryobi 40V, Snapper 82V, Worx 40V. We read that specificity as honesty rather than hype — check your model against it, because this is not a head that adapts to everything.

The Oregon is the most expensive head here, and it's the one we hand to someone with a mixed row of trimmers in the shed. Three bolt adapters — 7 mm, 8 mm and 10 mm — cover most straight-shaft brands, so the same head moves from a Stihl to a Husqvarna to a RedMax as machines come and go. Fifteen feet of .095 line fits inside, and it will take .105 if the grass demands heavier string.

One thing to know before you order: the bump feed is the weak spot. Line sometimes pays out short and needs a second tap, which is irritating on a head in this bracket. It rarely shows up on open lawn; it gets more noticeable on rough, uneven ground where the head is bouncing.

Reloading is what earns the price back. The spool comes off, the line goes in, and you're working again inside a minute, which is the difference between a professional head and a homeowner one. Where more than one brand lives in the garage, that plus a complete adapter set justifies the step up.

If you've fought an old-style Stihl head — the one that needs three hands and a prayer to restring — the AutoCut C 26-2 is the upgrade you keep meaning to buy. It's a genuine Stihl part, number 4002 710 2169, rated to 11,500 rpm, and the line winds onto a spool you can actually reach instead of threading by feel through a sealed cap.

Loading is the whole appeal. A fresh length goes in without dismantling anything, so a chore that used to eat ten minutes takes a fraction of that, and the feed pays out as you cut instead of stalling. It fits straight-shaft Stihl trimmers such as the FS110, and it makes the head that came with the machine feel like the weak link it was.

The cap is the part to watch. It can pop off mid-job, and a head without its cap is finished for the day, so seat it firmly and glance at it when you refuel. That caveat aside, this is the shortest path from a fussy Stihl to a pleasant one.

At the top of the price range sits a head that fits one family of trimmers only. The AH1520 is EGO's own POWERLOAD replacement, pre-wound with 16 feet of .095 dual-feed line, and it drops onto the ST1520 and ST1520S without adapters or modification. What you're paying for is the winding mechanism: feed line through and the head spools itself, which is the feature that made these trimmers appealing in the first place.

The mess is EGO's own model list. The bullets name the ST1520 and ST1520S while the title adds the ST1521S, ST1511S, ST1510S and ST1524. Match the number on your trimmer's shaft before you order, because no adapter kit bridges that gap.

We file it under repair parts rather than upgrades. A POWERLOAD trimmer with a chewed-up head is still a good machine, and 16 feet of line covers a normal suburban lot before a reload. For the right shaft, that is the whole case.

Three heads in one box changes how you treat a trimmer. With a spare on the shelf, a head that starts throwing line stops being a lost afternoon — you swap it, finish the job, and sort the old one out later. These are molded to Echo's Speed Feed 400 pattern and fit the SRM straight-shaft line, the PAS power units, and a run of Shindaiwa models.

Fit is the strength. They thread onto the Echo straight-shaft models without drama, and the 4.4-inch body clears the same guards as the factory head. Beyond that, treat the set as three consumables rather than one investment — plastic heads wear, and the point of buying three is that you are never stranded when one does.

That arithmetic works if you run Echo equipment and go through heads. It doesn't work if you're hoping one of these will outlast a genuine part — the third one in the box is there precisely because the first two are finite.

The SIMUSI box is the most complete here: an adapter kit of five nuts and six bolts in left- and right-hand threads, plus a dozen pre-cut one-foot lines in .095. That hardware is why it can sit on a clockwise or counterclockwise trimmer, and it's what to reach for when your shaft thread isn't one of the usual sizes.

The line is the interesting part. Those pre-cut lengths are triangular rather than round, and we like them more than we expected to — they bite in tall grass where round line slides. The reinforced nylon body shrugs off a knock against a fence post, and at 14.4 ounces it's substantial enough that it isn't the pick for a featherweight cordless trimmer.

'Universal' earns its quotation marks here. EGO and some Stihl shafts are where it misses, and it tops out at 3.0 mm line, so heavy-string users should look elsewhere. Get past the mount and it's a lot of head for the money.

A small iron plate spins at the center of the Deeploving head where it meets the ground, and it's the most interesting idea in this group. That's the spot a trimmer head wears through on concrete driveways and gravel paths — plastic grinding on grit until the eyelets open up and start snapping line. Fiberglass-reinforced polyamide around a metal wear plate is a design we hope other makers copy.

The rest is solid. It's a bump-feed head with a 14-foot spool of dual-color .095 line, and the two-tone string makes the ends easy to find when you're threading it — a small thing that saves real time on a cold morning. The 13-piece adapter kit covers most gas and cordless shafts, including Stihl, Greenworks 80V, and Kobalt 40V.

Where it struggles is on a big, hot-running gas unit, where the plastic mount is the part to watch. On a cordless trimmer or a mid-size two-stroke it does the job, and on abrasive ground it's the head we reach for first.

This is the other EGO head, and it does not fit the trimmers the AH1520 fits. The AH1522 is built for the telescopic-shaft POWERLOAD models, the ST1510T and ST1511T, and inside it's the same idea: 16 feet of pre-wound .095 dual-feed line and a head that winds itself when you feed line through.

Install is the easy part. It goes on like the part it replaces, and at a pound it keeps a telescopic shaft balanced instead of nose-heavy. What it isn't is a universal upgrade — if your trimmer isn't one of those two models, this head is a paperweight, and EGO's naming makes it easy to buy the wrong one.

We see it as a repair part with a narrow address. A trimmer that still runs needs a head, not a replacement, and this one restores the self-winding feature that made the machine worth owning. Confirm the model number on the shaft before you spend anything.