Updated September 16, 2026. Disclosure: As an Amazon Associate, we earn from qualifying purchases.
Quick answer: The EGO ST1623T is our best overall research-based pick for medium and large home lawns. Choose the BLACK+DECKER LSTE525 for a small maintained yard, the Greenworks STF457 when attachments matter, and the RYOBI RY402110 for the widest, heaviest-duty cutting setup.
Research note: We have not personally tested these four trimmers. Picks are based on current manufacturer documentation, manuals, kit contents, battery compatibility, warranty coverage, and owner-feedback patterns. Runtime and noise figures below are manufacturer claims.
Our cordless string trimmer picks
| Model | Best for | Cut | Line/head | Kit |
|---|---|---|---|---|
| EGO ST1623T | Best overall | 16 in. | 0.095 in.; LINE IQ + POWERLOAD | 56V 4.0Ah |
| BLACK+DECKER LSTE525 | Small yards and edging | 12 in. | 0.065 in.; EASYFEED | Two 20V 1.5Ah packs |
| Greenworks STF457 | Attachments | 16 in. | 0.080 in.; bump feed | 40V 4.0Ah |
| RYOBI RY402110 | Heavy-duty cutting | 15–17 in. | Three-in-one head; up to 0.105 in. | 40V 6Ah |
1. EGO ST1623T: best overall
EGO combines a wide 16-inch path and heavy 0.095-inch line with two convenience features. LINE IQ maintains line length without bumping, and POWERLOAD winds fresh line through the head. The kit includes a 4.0Ah battery, and EGO advertises up to 60 minutes of runtime. At 7.5 pounds before the battery, it is not a featherweight. It is the best match for buyers who will use the power and already value the EGO 56V ecosystem.
Read the full EGO ST1623T review →
2. BLACK+DECKER LSTE525: best for small yards
The LSTE525 is easier to justify for a modest lawn. Its 12-inch head fits tight spaces, the shaft converts to a wheeled edger, and the kit includes two batteries. EASYFEED advances line from the handle. The tradeoffs are thin 0.065-inch line, limited heavy-weed ability, and BLACK+DECKER’s listed 480-minute charge time. It is a maintenance tool, not an overgrowth-clearing machine.
Read the full BLACK+DECKER LSTE525 review →
3. Greenworks STF457: best attachment-capable choice
The Greenworks has a 16-inch path, brushless top-mounted motor, and a split shaft designed for compatible attachments. Greenworks lists up to 50 minutes with the included 4.0Ah battery. The clear drawback is its listed 9.7-pound weight before the battery. Choose it when a shared power head for trimming, edging, pruning, or cultivating is more valuable than minimum weight.
Read the full Greenworks STF457 review →
4. RYOBI RY402110: best heavy-duty option
The RYOBI adjusts from a 15- to 17-inch swath and includes bump-feed, fixed-line, and bladed-head configurations. Its 6Ah kit is aimed at longer sessions, with RYOBI claiming up to 67 minutes. This is a fixed-shaft trimmer rather than an attachment power head. It suits large properties and tough grass better than precision work around a compact garden.
Read the full RYOBI RY402110 review →
How to choose among these four
| If your priority is… | Start with… | Why |
|---|---|---|
| Least line-management hassle | EGO ST1623T | Automatic feed plus push-button winding |
| Small-yard value and edging | BLACK+DECKER LSTE525 | Compact head, guide wheel, two batteries |
| One motor for several attachments | Greenworks STF457 | Split shaft and broad attachment compatibility |
| Maximum swath and heavy line | RYOBI RY402110 | Up to 17 inches and three head setups |
What we did not rank by
Voltage by itself does not decide the winner. We also did not turn manufacturer runtime claims into direct laboratory comparisons because the companies use different conditions. Working weight, balance, line system, replacement parts, warranty, and the value of an existing battery platform often matter more during weekly use.
Frequently asked questions
What is the best cordless weed whacker for an average homeowner?
The EGO ST1623T is the strongest all-around choice here for a medium or large yard. For a small, routinely maintained yard, the lighter-duty BLACK+DECKER LSTE525 is usually the more economical fit.
How much voltage does a string trimmer need?
Small maintained yards can be handled by many 18V or 20V tools. Wider 40V to 56V models generally provide larger batteries, wider swaths, and heavier line for longer or tougher work. Compare the complete tool, not voltage alone.
Is thicker trimmer line always better?
No. Thicker line can last longer in heavy growth, but the head and motor must be designed for it. Use only the line diameter and type listed in the manual.
Should I buy a tool-only trimmer?
A bare tool can be the best value when you already own compatible batteries and a charger. New platform buyers should compare complete-kit prices and confirm that the included battery is large enough for the yard.