We Tested 22 Knife Sharpeners—These 7 Made Our Blades Look Like New

How We Tested

We purchased and tested 22 knife sharpener models—10 electric and 12 manual—to figure out which ones did the best job at restoring dull knife blades and which didn't. All were tested by our Lab team, which consists of testers with decades of experience in both professional and home kitchens, to compare their performance directly.

We Observed

• How easy or difficult the sharpeners were to operate: We tested both manual and electric sharpeners, noting their learning curve and ease of control. We also appreciated the models that came with easy-to-follow directions and video instructions.
• How sharp the knives turned out: We analyzed sharpness using a scientific tool called the Edge-on-Up, which measures the force needed to cut a standard reference material.
• How well the sharpened knives performed: We examined their ability to slice through paper, tomatoes, and carrots both before and after sharpening. For models that claim to accommodate serrated knives, we tested their slicing performance using a baguette.

We Rated

• Usability: Safety is always a concern when you're working with knives, so we focused on safety features like non-stick bases to keep the devices from slipping on the table and designs that keep the knives secured in place while sharpening.
• Design: We highlighted sharpeners that featured multiple stages for maximum efficiency or different slots for different blade sizes. Knife sharpeners can be bulky, so we also focused on compact sizes that you could store easily in your kitchen.
• Effectiveness: The Edge-on-Up tool helped give us an idea of each sharpener's efficiency, but we also tested our knives immediately before and after sharpening to gauge any noticeable differences.
• Value: Considering obvious price differences between electric and manual models, we looked at both budget-conscious and pricier knife sharpeners, assessing them on quality compared to cost. However, the best price will largely depend on your personal needs, such as how often you use your knives or how much you've already invested in your knife collection.

Other Options We Tested

• 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.
• Brod & Taylor Professional Knife Sharpener: It looks like a piece of contemporary sculpture, and its maker claims that its spring-loaded design is foolproof to use, but we had to manually hold the unit open to insert the knife and weren't able to get very good sharpening results at all. Add a hefty price tag, and you've got a sharpener we wouldn't recommend.
• Smith's CCKS 2-Step Knife Sharpener: This pocket-sized manual sharpener can be had for less than $5, and it actually did a decent job of sharpening knives—after 50 or more pulls through the abrasive—but it's very unstable, prone to slipping and potentially cutting hands and fingers.

What to Look for in a Knife Sharpener

Grit

Whether you’re working with a manual or electric sharpener, there are typically at least two grit options that go from coarse to fine. Coarser grit will shave off more metal to remove nicks, chips, and other damage, and it will get a very dull knife ready for finer sharpening. Finer levels of grit further refine the edge, giving it a high level of sharpness. Some sharpeners offer only two different grits, while others have a third (or even a fourth) level, which is similar to a honing steel used for a gentle touch-up. To sharpen a blade effectively, it’s ideal to use at least two different grits.

Size

Electric sharpeners are typically bigger than manual ones, and the number of grit options that any sharpener offers will also affect its size—one with two slots will be smaller than one with three or four. The slot width also matters, as narrower ones can't handle thicker blades, while wider ones might offer too much wiggle room to hold the perfect angle. One thing you don't have to worry about is blade length: Any of the slot-style sharpeners we tested can handle a short paring knife or 12-inch chef's knife with equal ease.

Material

The material a knife sharpener's abrasives are made out of is the main thing that affects how well it can sharpen knives. It might include steel, ceramic, or even diamond. Essentially, the harder the material used, the more effective the sharpener will be. If you have a ceramic knife, a ceramic abrasive won't be able to sharpen it. You'll need to look for a diamond sharpener. (Diamond also works well on steel blades but does tend to increase cost.)

Safety

The material the sharpener's body is made from makes a difference, as well. Nonstick rubber or plastic on the bottom helps keep the unit in place while you're using it; if the blade or sharpener slips, you could end up cutting yourself. Cheaper sharpeners also tend to be made of thin plastic, which is more likely to break if it drops off the counter. Some models even come with cut-resistant gloves as an additional safety element.

FAQs

How does a knife sharpener work?

A brand-new knife has (in theory) a perfectly straight blade, ground down to a precise cutting edge at a specific angle. As you use it, the metal on the edge gets damaged on a microscopic level, causing uneven spots that can get caught on foods and create a ragged tear rather than a clean cut. A sharpener does for a metal knife basically the same thing that sandpaper does for a wooden board: It shaves off a layer of uneven material to make the surface smooth and even again. Different models of sharpener use different materials and methods to remove metal, along with different methods of holding the knife in the correct position while doing so.

How do you use a knife sharpener?

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.

This process is essentially the same with both a manual and electric sharpener, but the motorized abrasives in an electric model will do more of the work for you. The most important thing is to try to use the same amount of pressure and the same angle with each pull through the slot—different models of sharpener make this easier or harder, depending on their design. Unless the directions specify otherwise, it should take three to five pulls through the coarse slot, and then just a couple through each finer slot, to sharpen the knife. If it's not as sharp as you like, try a few more pulls through the finest grit slot, and if that doesn't work, try the whole process over again.

What's the difference between a sharpener and a honing steel?

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.

According to Blake Hartley, Executive Chef at Lapeer Seafood Market, a sharpening steel removes material from your knife by moving the edge alongside the steel to restore the V-shape of a blunt edge. A honing steel is not used to sharpen but to restore the bent edge so that it's straight again.

How often should you sharpen your knives?

It really depends on how much you use them and how much abuse they take, but knives generally need sharpening once or twice a year. If a knife feels dull or has trouble cutting, sharpen it. Just note that every time you sharpen a knife, it removes a little bit of metal. After many repetitions, there won't be enough left to sharpen, and it'll be time to replace your knife.

"Keep knives in a covered, safe environment when not in use," says Hartley. "Do a weekly light hone with steel or stone, always wiping away particles with a clean dry towel. Don't feel like you have to work fast—with a process like this, form is everything. Work out the proper form first, and then the speed will come."

Can you sharpen kitchen shears with a knife sharpener?

It depends on the size! Kitchen shears are essentially two knives linked together, and like any other knives, they'll lose their edge after repeated use. Shears tend to have thicker blades than kitchen knives, but if your sharpener can accommodate them, it'll sharpen them. (This is easier if you can separate the blades of your shears, but it can even work with non-separable shears, if you're careful.) Take a close look at the blade edge, though: Many shears have a subtly serrated edge, which will be damaged by a sharpener that's only designed for straight blades.

How do you clean a knife sharpener?

Sharpening a knife blade removes tiny bits of metal, and those will need to be removed from the sharpener once in a while. Many models have a compartment in the bottom to collect metal filings, which you can simply dump into the trash and wipe clean with a wet cloth. (If there's no compartment, turn the unit over and lightly tap to get the filings out.) You can also clean the abrasive parts with a cloth or a soft brush dampened with water; make sure to let everything dry completely before using again. Unless the directions say otherwise, it's not a good idea to use soap or any kind of oil to clean a knife sharpener, as you can damage the abrasive.

Why Trust The Spruce Eats?

Donna Currie is a food and recipe writer, cookbook author, and product tester for The Spruce Eats. She spends a great deal of time in the kitchen chopping, slicing, and dicing. Her kitchen is stocked with knives ranging from budget-friendly to high-end picks, and she knows how to keep them sharp.

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.

Carrie Honaker, who updated this roundup, is a food writer who has wielded many knives over the years. As a restaurateur and avid home cook, she knows the importance of caring for your knives to maintain steady, sharp edges. Her work has appeared in many publications, including Bon Appetit, Allrecipes, and Wine Enthusiast.

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.

Sources

• Blake Hartley, Executive Chef at Lapeer Seafood Market