The Best Knife Sharpeners to Revive Dull Blades: Lab Tested and Approved

The top spot goes to the Longzon 4-in-1 Knife Sharpener

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The Spruce Eats / Chloe Jeong

Tested & Approved

Our No. 1 pick is the Longzon 4-in-1 Knife Sharpener. Testers were extremely impressed with this manual model's effectiveness in sharpening many types of blades, especially for its affordable price. If you're looking for budget-friendly options, we recommend the Priority Chef as a manual option or the Presto EverSharp for an electric pick.

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 sharpen 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.

To figure out which knife sharpeners are the best of the bunch, our Lab 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 knives) both before and after sharpening. They 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 before and after sharpening. Each sharpener was rated on ease of use, design, effectiveness, and value.

Here are the best knife sharpeners, according to our Lab tests.

Best Overall: Longzon 4-in-1 Knife Sharpener

5
Longzon 4-in-1 Knife Sharpener
Longzon 4-in-1 Knife Sharpener.

Amazon

What We Like
  • Non-slip grip and extended handle are very stable

  • Simple design and clear instructions

  • Low price

What We Don't Like
  • Cannot sharpen serrated knives

  • Works better on top and middle of knives than the heel

Our testers did not expect a knife sharpener at this low of a price to work as well as it does, but the Longzon 4-in-1 really delivers. As the name suggests, the manual sharpener has four slots—three successively finer ones for standard knives and an extra-wide one especially for sharpening scissors and shears. Some manual sharpeners take a little practice to use correctly, but the Longzon's design and included directions make things simple. There's even a QR code link to video instructions if you're more of a visual learner.

The Lab was impressed with this sharpener's safety features, too. Its non-stick bottom won't slide around on the counter, and the attached handle lets you steady the device with your off-hand for even more control. (It also comes with a pair of cut-resistant gloves for ultimate safety.)

Price at time of publish: $20.99

Style: Manual | Abrasive Materials: Steel, ceramic | Dimensions: 9 x 1.75 x 3 inches

Lab Test Takeaway

"I think anyone from a beginner to an experienced home cook to a culinary student and even a professional chef can really use and do well with the Longzon 4-in-1. No one should pass on this."

Best Budget Manual: Priority Chef Knife Sharpener

4
Priority Chef Knife Sharpener for Straight and Serrated Knives

Courtesy of Amazon

What We Like
  • Low price

  • Can sharpen straight and serrated knives

  • Sturdy construction

What We Don't Like
  • Not as effective as other sharpeners

  • Back-and-forth sharpening motion might be less safe

The Priority Chef Knife Sharpener features two sets of diamond-coated wheels that do a good job of restoring the edge to even a heavily dulled knife, and unlike our overall winner, the Longzon, it can handle serrated knives in addition to straight ones. Our Lab tests found it to be sturdy and simple to use, and it was able to restore a significant amount of sharpness, though not quite as much as other, pricier models. Still, it's a great deal for under 20 bucks. Most of the manual sharpeners we tested work by pulling the knife through the slot in only one direction, while this one has you "saw" back and forth. This doesn't interfere with its function, but testers worried it might make the knife more likely to slip out.

Price at time of publish: $15.95

Style: Manual | Abrasive Material: Diamond | Dimensions: 7.5 x 2.5 x 2.5 inches

Lab Test Takeaway

"The Priority Chef Knife Sharpener has simple design and compact size you could store anywhere in your kitchen."

Best Budget Electric: Presto EverSharp Electric Knife Sharpener

4.3
Knife Sharpener

Presto

What We Like
  • Inexpensive compared to other electric models

  • Works with straight or serrated blades

  • Easy to use

What We Don't Like
  • Only two different sharpening stages

  • Can leave scratches on blade

Electric sharpeners are easier to use than manual ones, but they're also quite a bit more expensive. The Presto EverSharp is one of the cheapest electric knife sharpeners we tested, but it still did a fantastic job of honing dull knives—straight and serrated—to a nice, sharp edge. (It even performed better on our tests than its slightly-more-expensive cousin, the Professional EverSharp.) Our testers did find that it left scratches on the side of the blade, which could lead to a damaged knife with repeated use.

Price at time of publish: $44.99

Style: Electric | Abrasive Material: Sapphirite | Dimensions: 9.9 x 7.2 x 4.8 inches

Lab Test Takeaway

"For an electric sharpener that gave me an almost 80-percent-sharper blade from the start, I would say this is a great value. A simple, easy-to-use design combined with that performance make this a more than fair value."

Best Electric: Wüsthof Easy Edge Electric Sharpener

5
Wusthof Easy Edge Electric Sharpener
Wusthof Easy Edge Electric Sharpener.

Amazon

What We Like
  • Easy to use

  • Significantly improved sharpness

  • Anti-slip base is very stable

What We Don't Like
  • Expensive

  • Knife doesn't fit snugly

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.

The flexible belt helps accommodate knives of all different sizes, though testers found that it also leaves a lot of wiggle room for the blade, making it somewhat difficult to keep knives at the exactly correct angle through the entire sharpening process. The Easy Edge theoretically can sharpen serrated knives, but it only sharpens the flat edge and not the serrations themselves, so our Lab recommends against using it with a serrated knife.

Price at time of publish: $200

Style: Electric | Abrasive Material: Steel | Dimensions: 9 x 4.5 x 5.5 inches

Lab Test Takeaway

"The Wüsthof Easy Edge is simple to use and sharpens very well, but with its high price, it's probably best for someone who spends a lot of time in the kitchen or is a professional chef."

Runner-Up, Best Manual: Chef'sChoice ProntoPro Manual Knife Sharpener

4.2
Knife Sharpener

Chef'sChoice

What We Like
  • Simple to use

  • Sharpens both sides simultaneously

  • Works with straight or serrated blades

What We Don't Like
  • Expensive for a manual sharpener

  • Can't sharpen thicker knives

The Chef'sChoice ProntoPro has the most advanced technology of any of the manual sharpeners we tested. Its diamond abrasive wheels sharpen both sides of the blade at the same time, and its three-stage sharpening process creates a two-facet, arch-shaped edge that the brand says will stay sharper longer. In our tests, the ProntoPro was absolutely able to improve the sharpness of both standard and serrated blades, but didn't quite bring anything back to like-new quality. Its slots are also too narrow to accommodate a thicker knife, like a cleaver.

Price at time of publish: $70

Style: Manual | Abrasive Material: Diamond | Dimensions: 9.25 x 2 x 2 inches

Lab Test Takeaway

"The ProntoPro is extremely easy to use, and the instructions are very clear on what sharpener section to use and how to use it. Handheld and easy to hold against the table. This is a good home product."

Best for Beginners: Chef'sChoice 320 Diamond Hone Knife Sharpener

4.5
Chef'sChoice 320 Diamond Hone Knife Sharpener
Chef'sChoice 320 Diamond Hone Knife Sharpener.

Amazon

What We Like
  • Slots hold the knife at the perfect angle

  • Easy to use, with simple instructions

  • Works with straight or serrated blades

What We Don't Like
  • Only two different sharpening stages

  • Fairly expensive

Sharpening a knife to the finest possible point is a true art that takes a lot of practice and technique. The Chef'sChoice 320 takes out a lot of guesswork, thanks to its firm-fitting sharpening slots that hold the knife at just the right angle. This machine uses two different textures of diamond abrasive to hone blades and works with standard or serrated knives, but testers missed a third, coarsest abrasive that other models use to make sharpening faster.

Price at time of publish: $114.99

Style: Electric | Abrasive Materials: Diamond, steel | Dimensions: 10.6 x 6.4 x 6.3 inches

Lab Test Takeaway

"The Chef'sChoice 320 made light work of sharpening the knife and creating a good edge. Directions are very specific and tell you which knives to sharpen on which stage, and how long to sharpen them."

Best Splurge: Chef’sChoice 130 Professional Electric Knife Sharpening Station

4.7
chefschoice-electric-knife-sharpening-station

Courtesy of Amazon

What We Like
  • Gets knives extremely sharp

  • Easily sharpens all parts of the blade

  • Works with straight or serrated blades

What We Don't Like
  • Complicated instructions

  • Expensive

If you're the kind of person who has an opinion on the proper angle for knife sharpening and knows what a burr is, you'll want a Chef'sChoice 130. Its three stages use a diamond abrasive to prepare the blade, steel to set the cutting edge, and lastly a flexible stropping disc for final perfection of the knife. This model significantly improved sharpness in our tests and works with serrated knives—something many other sharpeners can't do—but our testers found the instruction manual a bit lengthy and dense. However, if you follow it properly, including looking for a burr (which, for the record, is a very thin lip of metal that hangs over the cutting edge and indicates it's time to sharpen the other side of the blade), you'll have great success.

Price at time of publish: $143

Style: Electric | Abrasive Materials: Diamond, steel | Dimensions: 12 x 6 x 6.25 inches

Lab Test Takeaway

"While this device seems a little pricey, I would consider spending the money given the results that it produced."

Final Verdict

Despite its low price, the Longzon 4-in-1 Knife Sharpener came out tops in our tests. This manual sharpener is simple to use, comes with effective instructions, and works well on many different sizes of blade. For those on a budget, the Priority Chef is what we recommend as a manual option, but the electric Presto EverSharp is excellent, too.

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 knives were tested in our Lab to compare their performance directly, examining 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. In addition, we analyzed sharpness using a scientific tool called the Edge-on-Up that measures the force needed to cut a standard reference material. Testers also rated the sharpeners on ease of use, construction and design, and ease of cleaning.

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, well, you get what you pay for. The Lab found that it did just an OK job at sharpening, while its feet let it slide around on the countertop, 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 our testers found that they 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 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 effectively sharpen a blade, it’s ideal to use at least two different grits.

PriorityChef Diamond Coated Knife Sharpener
The Spruce Eats / Hailey Eber 

Size

Any time you’re looking to purchase a new kitchen gadget, evaluating its size is essential. Do you have the storage space for it? Will it fit comfortably on your counter when you’re using it? Is it large and bulky or light and tiny?

Electric sharpeners are typically bigger than the 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. This might include steel, ceramic, or even diamond. Essentially, the harder the material used, the more effective the sharpener will be. Plus, if you have a knife made from ceramic, 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.)

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.

Price

The knife sharpeners we tested sell for prices from $5 to $200—now that’s a range. Manual sharpeners are almost always less expensive than electric ones, but they also take a little more skill and practice to sharpen knives most effectively. If you’re working with expensive chef's knives that you use fairly regularly, it’s probably in your best financial interest to invest in a quality knife sharpener: Proper use can make your pricey blade last much longer. That said, many manual options can do a fantastic job of creating a sharp edge, potentially even sharper than an electric model—if you know what you're doing and are willing to put in a little more time.

PriorityChef Diamond Coated Knife Sharpener
The Spruce Eats / Hailey Eber 

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. A steel 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.

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.

Can you sharpen kitchen shears with a knife sharpener?

Maybe! 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 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 this 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. 

Additional reporting by
Carrie Honaker
Carrie Honaker The Spruce Eats
Carrie Honaker is a freelance writer specializing in food, wine, travel, and culture. Her work has appeared in Bon Appetit, Wine Enthusiast, Allrecipes, and more.
Learn about The Spruce Eats' Editorial Process
and
Rebecca Treon
Rebecca Treon
Rebecca is a freelance writer specializing in food, travel, and lifestyles. Her work has appeared in BBC Travel, Huffington Post, Hemispheres, and Thrillist. She is the Denver & The West Correspondent for Time Out and is writing a book about Colorado's foodways.
Learn about The Spruce Eats' Editorial Process
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