There are only three real approaches to putting an edge back on a chainsaw chain, and the marketing around all of them is noisy. Here is what actually separates them once you have used all three for a season.
Hand filing
A round file of the correct diameter, a flat file for the rakers, and a depth gauge tool. That is the whole kit, and it costs less than a tank of fuel.
The strengths are real: nothing is more portable, nothing is cheaper, and a skilled filer can touch up a chain in a few minutes without removing anything. Files also remove very little metal per stroke, so a hand-filed chain often lasts more sharpenings than a ground one.
The weaknesses are equally real. Hand filing is a genuine skill that takes a season to develop. The angle drifts as your arms tire. You cannot see the side plate angle while you work. And filing a badly dulled chain — one that hit dirt or a nail — takes a very long time, because you are removing a lot of hardened steel with a hand tool.
Bench grinders
A mounted electric grinder with an abrasive wheel, angle stops and a chain vise. This is what the dealer uses when you drop a chain off.
Strengths: speed and repeatability. Once the grinder is set up for a chain type, every cutter is ground identically and you can put a rock-damaged chain back into service in minutes rather than an hour. For a shop turning around several chains a day, nothing else makes sense.
Weaknesses: it is a workshop tool. You must remove the chain from the saw, carry it to the bench, and set the machine up. Grinders also remove metal aggressively, and an inexperienced operator can overheat and blue the cutters, which destroys their temper permanently. Then there is price — a decent professional grinder costs several hundred dollars, more than many homeowners paid for the saw.
Portable guided sharpeners
The third category sits between the other two: a compact tool that clamps to the guide bar and sharpens each cutter in place, either with a file or with a small rotating burr driven by a hand crank.
Strengths: the guide fixes the angle mechanically, which gives you consistency close to a grinder without needing the skill of a hand filer. Because it clamps to the bar, the chain never comes off the saw, so it works on site, up a tree, or on a tailgate. Crank-driven versions cut noticeably faster than a file per tooth, because the burr does the work rather than your forearm.
Weaknesses: you are still working tooth by tooth, so a full bar takes minutes, not seconds. Burrs are consumables and eventually need replacing. And for very large professional-pitch chain in high volume, a bench grinder is still the faster machine.
Time per chain, realistically
A confident hand filer touching up a lightly dulled 18" chain: 8–12 minutes. The same chain badly dulled: 25–40 minutes. A bench grinder, once set up and with the chain already removed: 6–10 minutes of machine time, plus the removal, transport and refitting. A crank-driven bar-mounted sharpener on a lightly dulled chain: roughly 2–5 seconds per tooth, so around 3 minutes for a typical bar, done where you are standing.
Which one should you own?
If you cut a few times a year and enjoy the craft, a good file kit is genuinely enough. If you run a sharpening service or process many chains a week, buy a bench grinder and never look back. For everyone in the middle — the arborist, the landscaper, the homeowner with a wood stove — the deciding factor is not precision but friction. The best sharpening method is the one you will actually use between tanks of fuel, and that means the one you can do without removing the chain or leaving the job site.
That is exactly why portable guided sharpeners have taken over so much of this market in the last few years, and why our top pick sits in that category.