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Maintaining the poise and balance of the older trimmer, the Stihl FSA 57 Cordless Grass Trimmer is the best cordless strimmer for medium to large lawns. It might not have a rotating head, but it’s easy to manoeuvre and extremely powerful. With the new easy-to-load spool, this grass trimmer is simple to maintain and has the option of plastic blades, too.


  • Powerful
  • Well balanced
  • Decent battery life


  • Head doesn’t rotate


  • UKRRP: £146
  • USARRP: $199.95
  • EuropeRRP: €159
  • Canadaunavailable
  • Australiaunavailable

Key Features

  • WeightAt 3.5kg with the battery, this is a pretty light cordless trimmer. It’s exceptionally well balanced, too, making it easy to use.
  • Cutting widthA 280mm cutting width from either the line or optional Polycut blades is wide enough to make short work of grass in large gardens.
  • Battery lifeThe recommended AK10 battery delivers up to 25 minutes of runtime, which is more than enough to zip around a medium to large garden. Larger batteries are available, although they add to the weight of the device.


The original Stihl FSA 56 was one of our favourite grass trimmers. It’s fair to say that the new Stihl FSA 57 Cordless Grass Trimmer is a welcome upgrade. It maintains the original’s balance and ease of use, but updates the mowing head with a model that’s easier to refill with cutting line, and you get the option of using Polycut blades instead.

Excellent ergonomics, quiet in use and compatible with Stihl’s AK battery range, this is the ultimate grass trimmer for medium to large gardens.

Design and Features

  • Exceptionally well balanced
  • Smart safety features
  • Easy to reload with line

From the outside, the Stihl FSA 57 doesn’t look very different to the FSA 56. There are a few cosmetic differences on the outside – the head is more orange on the newer model, for example – and the new model is a touch heavier as well, at a still light 3.5kg (including battery).

This isn’t necessarily a bad thing, though: the FSA 56 was ergonomically brilliant, and so is the FSA 57. Once you’ve grabbed the controls with one hand, and the handling loop with the other, the FSA 57 naturally leans up against your forearm providing good balance and control.

You can adjust the length of the shaft to suit your height, and adjust the angle of the loop, too, so it’s easy to get the trimmer just right for you.

Stihl FSA 57 Cordless Grass Trimmer extension button

There’s a flip-down spacer guard at the front, which you can use to make sure that you don’t get the trimmer too close to your prized plants or flowers.

Stihl FSA 57 Cordless Grass Trimmer spacer

The only thing that the FSA 57 doesn’t have is a rotating head for trimming the edge of paths, which the cheaper Stihl FSA 45 (an integrated battery model) does have.

Compatible with AK batteries, Stihl recommends the AK10, since it provides a good compromise between weight and runtime. If you want the FSA 57 to run for longer, you can use the larger AK20 or AK30 batteries.

Stihl sells the FSA 57 barebones (no battery or charger) for a very reasonable £149, although you can buy it with the AK10 and AL101 charger for £239. That can top the AK10 battery up to full power in 1hr 35mins or to 80% in 1hr 10mins. 

If you want faster charge times, opt for the AL500 charger, which gets you a full charge on an AK10 battery in just 45 minutes. The faster charger is also useful with larger batteries, of the type you may want for a lawnmower, such as the Stihl RMA 235.

Batteries have two positions inside the grass trimmer. The first is a locking position, where the battery can’t fall out, but it doesn’t make contact. That’s great for transport, and means you can’t accidentally set the trimmer off.

Stihl FSA 57 Cordless Grass Trimmer battery in safety position

Push the battery in fully and it makes the FSA 57 live and ready to use. In either position, you can press the button on the back of the battery to see the rough charge level, indicated by the LEDs.

Stihl FSA 57 Cordless Grass Trimmer battery indicator

To start the FSA 57, you have to slide the switch on the handle forward and then grip the two triggers. Once on, you can release the slider. It’s a good setup: safe enough to prevent accidental engagement, but easy enough to use, even if you have to start and stop regularly.

Stihl FSA 57 Cordless Grass Trimmer controls

Stihl has redesigned the cutting attachment, shipping the FSA 57 with the new C3-2 Mowing Head, which comes with 1.6mm of cutting line (it can take up to 8m), although you can fit a thicker 2mm line (up to 5m).

Stihl FSA 57 Cordless Grass Trimmer line in spool

The main difference with the new cutting head is that it’s far easier to reload. With the old FSA 56, you had to cut your line in half, then feed each half into the spool. With the FSA 57, you just slide the line through until you have equal amounts of line on either side of the spool. 

Line is bump-fed (just tap the FSA 57 on the ground) with an excellent mechanism that worked perfectly for me. If you do release too much line, there’s a blade beneath the cutting hood that will trim to size automatically.

If you prefer blades, which can be good for tougher jobs and larger areas, there’s an optional Polycut Mowing head available, which takes clip-in plastic blades instead. Both cutting attachments have a cutting width of 280mm.


  • Excellent cutting performance
  • Quiet
  • Decent battery life

Using the Stihl FSA 57 over a period of a few weeks, I was impressed at how well it performed. Using the 1.6mm line, I found that the trimmer coped with long grass perfectly, leaving a neat cut, and letting me get right up to the edges. 

Stihl FSA 57 Cordless Grass Trimmer grass before being cut
Stihl FSA 57 Cordless Grass Trimmer grass after cutting

Even when dealing with some thicker weeds and some clumps of overgrown grass, the FSA 57 proved itself to be exceptionally powerful, cutting without hesitation.

Getting into edges means flipping the trimmer up, which isn’t quite as easy as having a rotating head. However, the low weight and excellent ergonomics mean that using the FSA 57 in this way isn’t too much of a chore.

Battery life is quoted at up to 25 minutes, although you may get slightly less if dealing with thicker grass or weeds. This was accurate, and a full charge delivered around the 25-minute figure – a small improvement on the FSA 56’s runtime. Certainly, with the AK10 battery, you’ll be able to manage a large lawn.

Evaluating the sound while cutting grass from ear height, the FSA 57 measured 78.8dB. That’s very quiet for a grass trimmer and means that you’ll be able to use this tool without ear defenders.

Best Offers

Should you buy it?

If you have a medium to large lawn and need a flexible and powerful grass trimmer, this is an excellent choice. Use the AK system of batteries, and you’ll find lots of tools in the range that share the same units, keeping the cost of future purchases down.

For small lawns, the FSA 57 is probably a bit too big. There also isn’t a huge difference between the FSA 56 and this model, so there isn’t much reason to upgrade if you already own the older tool.

Final Thoughts

If you have an FSA 56, then there isn’t quite enough of a difference between it and the FSA 57 to warrant an upgrade. For those looking for a new grass trimmer, the FSA 57 is an excellent choice for medium to large gardens. It’s easy to use, easy to reload and offers up lot of power. It comes highly recommended. For options for different-sized lawns, check out my guide to the best grass trimmers.

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How do you change the line on the Stihl FSA 57?

With this model, you can swap spools, pre-wound with cutting line, or you can feed the new line through the existing spool until you get an equal amount on either side.

Does the Stihl FSA 57 have a rotating head?

No. To trim the edges of borders with this model, you’ll have to tilt the trimmer.

What batteries is the Stihl FSA 57 compatible with?

It works with the AK series of batteries, with Stihl recommending the AK10 – this delivers 25 minutes of runtime and the perfect weight to best balance the trimmer.

Test data

Sound (normal)


Release Date
First Reviewed Date
Model Number
Cutting width
Strimmer type
Adjustable length
Cutting tool

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