To discover the best knife sharpeners on the market, we collected an array of dull knives—plus several boxes of Band-Aids—and tested their performance slicing through paper, carrots, and tomatoes (and a baguette, for serrated blades), both before and after sharpening. We also measured each knife's sharpness scientifically, using an Edge-on-Up tool to record the exact amount of force needed to cut through a standard material.

Pull the knife blade along the sharpening steel towards you, with enough gentle force that you can hear a grinding noise.

German company Wüsthof has been making world-famous knives for more than 200 years, so it makes sense that its sharpening tools are also high-quality. The Easy Edge features a spinning belt that runs at three separate speeds for coarse honing up to final polishing, along with a one-touch program with indicator lights for each stage. An integrated suction fan also keeps dust out of the way. Repeat this action three to six times. You can go for three if your blade is just a bit dull, and more if it's blunter. Rebecca Treon, who also updated this piece, is a food writer, experienced home cook, and mother of two. Her work has been featured in BBC Travel, Huffington Post, Hemispheres, and Thrillist. Work Sharp Electric Culinary E2 Kitchen Knife Sharpener: This sharpener is easy to use and has an excellent price for an electric model, but you get what you pay for. We found that it did just an OK job at sharpening, while its feet let it slide around on the countertop, which is a definite safety hazard.

It doesn’t matter which knives you buy—they'll all need to be sharpened periodically. Besides making it easier to cut and chop, keeping knives sharp is also safer for your fingers: Dull knives can drag or skip while cutting, which can increase your chance of injury. How often you need to use a knife sharpener depends on exactly how often you use the knife, what you cut, and what surface you cut on, but professionals typically recommend sharpening once or twice a year. Handheld manual knife sharpeners are designed to keep your blade fresh, and you should use them to top up the blade after every few hours of use. An electric knife sharpener or whetstone would be your best bet for a fully dulled knife. Each knife sharpener will have its own specific directions, and you should always follow those, but in general, you insert the blade into the slot and pull it through with even pressure several times. It's important to make sure the full blade passes over the abrasive, all the way from heel to tip. Then, you repeat the process on the other side of the blade (though some sharpeners work on both sides at once), first using the coarsest slot and then each of the finer ones. We rate each knife sharpener on how easy it is to set up and use, plus how easy the instructions are to follow. Things we learnt testing knife sharpeners Jason Horn, a commerce writer for The Spruce Eats, updated this roundup to include data from our extensive tests of 22 sharpeners—10 electric and 12 manual—by both freelance testers and in our Lab in Birmingham, Alabama.A honing steel is a long rod, often included in knife sets, along which you run both sides of the blade before you start slicing and dicing. It helps maintain the integrity of the blade, straightening out some of the microscopically uneven spots on the edge without actually removing any metal. Used regularly—as in every few times you use the knife—it can help stave off dullness, but you'll still need to sharpen your knife on occasion. If your sharpener has more than one setting, select 'coarse' for very blunt knives. The fine or honing setting is for everyday knife maintenance. All that’s left to do is dig out your blunt and damaged Global Knives and get them sent off to us to get them sharper than new!