3 Best WORX String Trimmers with 4.0 Ah, Compared

Quick picks

The best fit for you

• You need the widest cutting path for dense weeds WORX 15-Inch Brushless 40V String Trimmer Its 15-inch cutting width handles thick vegetation faster than narrower models.
• You want edging and mowing in one small tool Worx 20V 13-Inch Cordless Trimmer and Edger This 3-in-1 design trims, edges, and mows with a compact 13-inch head.
• You prefer the lightest weight for easy handling WORX 20V 12" Cordless Trimmer At 5.3 pounds, it is the lightest option for reducing user fatigue.

Our 3 picks

1 Best overall

WORX 15-Inch Brushless 40V String Trimmer

Best for: Users needing wide cuts and long runtime

Battery Capacity

4.0 Ah (what this guide is about)

Voltage

40V

Cutting Swath

15"

Power Source

battery

Motor Type

brushless

Line Feed System

bump feed

View on Amazon: WORX 15-Inch Brushless 40V String Trimmer Affiliate link

This WORX 15-inch cordless string trimmer delivers gas-like power with a 40V brushless motor. It includes a 4.0 Ah battery for extended runtime and variable speed control. The 15-inch cutting width and bump-feed line system help you finish jobs faster. It weighs 9.42 pounds for easy maneuvering. This tool suits users wanting a powerful, wide-cut trimmer that integrates with the WORX Power Share platform.

Pros

• 40V brushless motor provides 40% more power than first-gen models.
• 15-inch cutting swath covers more ground per pass.
• Includes 4.0 Ah battery for optimal runtime.
• Variable speed control adjusts power for different tasks.
• Bump-feed head allows quick line advancement.

Cons

• Heavier at 9.42 pounds compared to lighter 20V models.
• No auto-feed line advancement; requires manual bumping.
• Single speed setting lacks multiple power presets.

Good fit if

• You need a wider 15-inch cut to clear thick weeds faster.
• You already own WORX 40V Power Share batteries.
• You want a brushless motor for longer tool life.

Skip if

• You prefer a lighter tool under 7 pounds.
• You only have 20V batteries and want to avoid buying 40V.
• You want auto-feed line advancement for hands-free operation.

Verdict: WORX 15" 40V Cordless String Trimmer is a powerful option for users who prioritize cutting width and runtime. It fits those who already use the 40V platform and need to tackle dense vegetation efficiently.

2 Best budget

Worx 20V 13-Inch Cordless Trimmer and Edger

Best for: Edging and mini-mowing in small yards

Battery Capacity

4.0 Ah (what this guide is about)

Voltage

20V

Cutting Swath

13 in

Power Source

battery

Motor Type

brushless

Shaft Type

telescopic

View on Amazon: Worx 20V 13-Inch Cordless Trimmer and Edger Affiliate link

This WORX model features a 20V brushless motor and a 13-inch cutting swath. It includes a 4.0Ah battery for extended runtime. The 3-in-1 design allows switching between trimming, edging, and mini-mowing. A 90-degree pivoting head handles slopes. The telescopic shaft adjusts to your height. It suits users needing versatile yard tools without gas maintenance.

Pros

• Brushless motor delivers high torque
• Includes 4.0Ah battery for longer runtime
• 3-in-1 trimmer, edger, and mini-mower
• Push-button line feed system

Cons

• 20V system has less power than 40V competitors
• 13-inch cutting width is narrower than standard trimmers
• Mini-mower function has limited capacity

Good fit if

• You need a tool that edges and mows
• You have slopes or uneven terrain
• You want a lightweight 20V system

Skip if

• You require a 40V or 80V platform
• You need a wide 17-inch cutting swath
• You only want a standard string trimmer

Verdict: WORX 20V 13" 3-in-1 Cordless Trimmer fits users who want edging and mini-mowing capabilities in a compact 20V package. It is ideal for small yards with slopes rather than large open lawns.

3 Best 12-inch

WORX 20V 12" Cordless Trimmer

Best for: Users wanting a combined trimmer and mower kit

Battery Capacity

4.0 Ah (what this guide is about)

Voltage

20V

Cutting Swath

12 in

Power Source

battery

Cutting Width

12-Inch

Mowing Function

2-in-1

View on Amazon: WORX 20V 12" Cordless Trimmer Affiliate link

This WORX kit includes a 20V 12-inch string trimmer and a 40V 17-inch lawn mower. It comes with two 4.0 Ah batteries and a dual charger. The trimmer converts to an edger and features instant line feed. The mower uses Intellicut technology to manage power. This bundle suits you if you need both tools in one package with shared battery power.

Pros

• Includes 20V 12-inch trimmer and 40V 17-inch mower
• Comes with two 4.0 Ah batteries and dual charger
• Trimmer converts to wheel edger in seconds
• Mower features Intellicut torque on demand technology

Cons

• Trimmer has a narrower 12-inch cutting swath
• Kit includes two separate voltage systems
• Heavier and bulkier than trimmer-only models

Good fit if

• You want a trimmer and mower in one kit
• You need a 12-inch cutting width for precision
• You prefer shared battery systems across tools

Skip if

• You only need a string trimmer
• You prefer a single 40V voltage platform
• You need a wider 15-inch cutting swath

Verdict: WORX WG911 2-in-1 Trimmer and Mower fits you if you want a complete yard care kit with shared batteries. It offers precision trimming and mowing in one purchase.

Specifications side by side

How to choose the right one

1. Check voltage for power

   Voltage indicates the motor's potential power output. You have three options here, but they differ significantly. The top pick uses 40V, which generally provides more torque for dense weeds. The other two models use 20V, which is sufficient for lighter tasks. If you have thick brush, the higher voltage model is better. For small yards with soft grass, the 20V units are adequate. Match the voltage to the toughness of the vegetation you typically encounter in your yard.

2. Compare cutting width

   Cutting width determines how much ground you cover per pass. The WORX 15-Inch Brushless model offers the widest path at 15 inches. This reduces the time needed to trim large areas. The 20V models offer 12-inch and 13-inch widths. Narrower heads are easier to maneuver around tight obstacles like fences and flower beds. If speed is your priority, choose the 15-inch option. If precision in tight spots matters more, the narrower 12-inch or 13-inch models are suitable.

3. Review weight and size

   Weight affects comfort during extended use. The WORX 20V 12-inch Trimmer is the lightest at 5.3 pounds. This makes it easy to hold for long periods without fatigue. The 20V 13-inch model weighs 6.62 pounds. The 40V 15-inch model is heaviest at 9.42 pounds. Heavier tools may cause arm strain if you have a large yard. Consider your physical strength and the size of your area. Lighter models are better for smaller yards or users who prefer less effort.

4. Consider mowing functions

   Some models include additional functions beyond trimming. The WORX 20V 13-inch model is a 3-in-1 unit that trims, edges, and mows. This versatility is useful for small yards where you need multiple tasks done. The 20V 12-inch model is a 2-in-1 trimmer and mower. The 40V 15-inch model is a dedicated string trimmer. If you want an all-in-one tool for edging and mini-mowing, the 3-in-1 option is ideal. If you only need trimming, the dedicated model is simpler.

5. Verify battery compatibility

   All listed models use 4.0 Ah batteries. This ensures compatibility if you already own WORX 40V or 20V tools. You can share batteries across devices, which reduces the need to buy extras. Check your existing battery voltage to match the tool. The 40V trimmer requires a 40V battery. The 20V trimmers require 20V batteries. Mixing voltages is not possible. Ensure your existing batteries match the voltage of the new tool you choose to avoid compatibility issues.

Frequently asked questions

See also

• best WORX 20V string trimmers
• WORX vs CRAFTSMAN string trimmer
• best string trimmers with 4 0 ah
• best impact wrenches with 4 0 ah