I’m a staff writer on Wirecutter’s kitchen team, as well as a cookbook author and an avid home cook. I’ve also tested and written about drip coffee makers, knife sets, and more.

For this guide:

• I spent over 30 hours researching 25 knife sharpeners and testing the 15 most promising models.
• I spoke with a chef, a butcher, and a knife forger to get a sense of the different types of knife sharpeners and what home cooks should look for in a good one.
• I built on hours of research and testing put in by senior staff writer Tim Heffernan, the previous author of this guide.
• Like all Wirecutter journalists, I review and test products with complete editorial independence. I’m never made aware of any business implications of my editorial recommendations. Read more about our editorial standards.

If you own a knife, you’ll eventually need to sharpen it.

There are many ways to do this—from learning to use a whetstone to paying a service to do it for you. But we’ve found that a good electric sharpener is the quickest, easiest, and safest way to get your knives sharp again. Though our picks are pricey, they can last years, and they’ll also save you from spending money on new knives when your blades inevitably dull.

We know many fear that electric sharpeners remove too much metal, causing permanent damage to knives. “Using a bad electric knife sharpener is just about the worst thing you can do to your knives,” veteran cook Chad Ward warns in his book An Edge in the Kitchen: The Ultimate Guide to Kitchen Knives. He points out that “poor electric sharpeners have given the entire genre a bad name,” but he relents that “Chef’sChoice makes a number of well-designed electric sharpeners.”

We agree, because our picks include built-in guides, to ensure a consistent angle, and diamond abrasives that won’t de-harden the blade. The user manuals also offer clear instructions to avoid over-sharpening, coaching users on the number of pulls, on using light downward pressure, and even on how to detect a burr to determine that a knife is sufficiently sharpened. We like Chef’sChoice electric sharpeners because they’re at-the-ready and fast, and they’re the easiest to use of all options.

That said, we also tested a few purportedly gentler methods, such as rolling sharpeners and some manual, hand-held sharpeners. And for those who are interested in whetstones, we provide some tips below.

Don’t forget, no matter which method you use, you should also maintain your knives’ sharpness by using a honing steel between sharpening.

For this guide, we focused on manual, electric, and rolling-style sharpeners that use abrasives to put a sharp edge on knives. Our past testing showed the best of them to be safe and simple to use, capable of creating a truly excellent edge, and effective on knives of multiple sizes and styles.

We chose not to test sharpening stones and jig systems. While both can produce brilliant edges, sharpening stones have a steep learning curve, with lots of ways to damage your knives (video). And jig systems are complicated to set up and overkill for most home chefs.

The manual and electric sharpeners we did test came in various sizes and designs, but we wanted all of our contenders to share a few characteristics:

Easy to use: Electric models have a powerful motor that sharpens knives quickly and without straining. Manual and electric sharpeners should have built-in guides to help you orient and keep the knife at the correct angle. Our picks don’t require a lot of guesswork or instruction to use.

Creates a keen edge along the entire blade: We looked for sharpeners that could consistently produce knives capable of slicing a ripe tomato in one swift stroke, without sawing, tearing the skin or flesh, or requiring you to press down hard on the blade. We also looked for sharpeners that created a consistently sharp edge from the heel of the blade (near your hand) to the tip.

Can sharpen multiple kinds of knives: Almost every kitchen will have a few different types of knives—at the very least a chef’s knife and a paring knife, and often a slicer, a boning/filet knife, and a carving knife. Our picks could handle all of them. Though all of our picks can sharpen serrated knives, we did not prioritize that during testing because serrated knives’ teeth don’t need to be sharpened as often.

Does the sharpening angle matter?

One thing we didn’t give too much weight to was whether a sharpener was European-style versus Asian-style, or whether a sharpener offered both options. In the past, European-style knives were made of softer steel and sharpened at around a 20-degree angle, while Asian-style knives were made of harder steel and sharpened at a more-acute 15-degree angle or so. This distinction no longer holds: The modern alloys now used by knife makers worldwide are generally tough enough to support acute edges, regardless of how hard they are.

If you have quality knives that are older, however, it’s a good idea to pay attention to the angle of your knife. Chelsea Miller, a knife forger, points out that to ensure your knife has a long life, you should sharpen it to the angle at which it was manufactured. “If you can’t find the specs of the angle, the difference between 15, 18, or 20 degrees is minute, and that range is usually a good place to be.” In general, a smaller angle means a sharper knife. So a 15-degree angle is ideal for intricate cutting tasks, such as sushi, while 20 degrees is the usual angle for basic kitchen tasks. In general, a higher angle allows your knife to stay sharp longer.

To test knife sharpeners, we needed dull knives. We purchased three new Victorinox Swiss Classic chef’s knives (our budget pick), and we destroyed their razor-sharp factory edges by chopping and sawing on 80-grit sandpaper for two minutes. Then we sawed, scraped, and twisted the blades on 220-grit sandpaper for another two minutes. We repeated this process after every test, to ensure that all of our sharpener contenders faced an equal challenge.

Our knives arrived sharp enough to cleanly slice the tomatoes with virtually no downward pressure on the blade—their weight alone was enough. We took that as a benchmark for the sharpeners’ performance: Tomatoes, with their tough skins and soft interiors, quickly expose poor-quality edges. Dull knives will squish them rather than slicing them, and coarse or uneven edges can tear the skin. To judge the quality of each sharpener’s performance, we dulled the knives, resharpened them, and then sliced through pounds of tomatoes.

We also invested in an Edge-On-Up sharpness tester, which gave us some more data points before and after sharpening. It works by measuring the force, in grams, required to cut through a wire, the idea being that the duller the knife, the greater the force (weight) required. A sharp knife can slice through the wire with practically its own weight and barely any force. Fewer grams registered reveals the sharpest edge.

We followed each sharpener manufacturer’s instructions carefully. Since we destroyed the knives’ edges before each test, we first operated the sharpeners on their “reshaping” setting, which forms a whole new edge on a knife by rapidly removing metal with high-speed or coarse abrasives. Then we completed each contender’s sharpening and (when this was an option) honing operations, in which the new edge is refined using slower speeds and/or finer abrasives.

In addition, we tested our final contenders in a more real-life setting (minus the sandpaper torture), using our test kitchen’s knives as well as those of staffers; we tested knives with full and half bolsters, and of varying sizes and states of disrepair. This gave us a sense of how versatile each sharpener was in terms of knife type, and it also forced the sharpeners to work intensively, potentially revealing inadequate motors or other weaknesses. And it forced us to get real about how likely we were to use these devices consistently at home.

The Chef’sChoice 1520 and the Chef’sChoice Trizor 15XV electric sharpeners produced the keenest and most consistent edges of all the knife sharpeners we tested. And they did so more quickly and reliably than any other sharpener. Because of their design, it’s virtually impossible to make a mistake, even if you’ve never used a knife sharpener before. We continually turned to the 1520 in particular to resharpen knives when other sharpeners failed to do so. The 1520 even produced a razor edge on knives we’d feared might have been irretrievably dulled.

They consistently turned out razor-sharp edges. The 1520 and the Trizor 15XV dependably returned badly dulled knives to an extremely sharp edge. Also crucial, they sharpened the blades evenly from heel to tip, leaving no dull spots, whether the knife was full or half-bolstered, expensive or inexpensive. We found both models to be identical in their operation, with superior sharpening abilities.

After being sharpened with these picks, our knives effortlessly sliced through tomatoes with practically the force of their own weight, and the sharpness tester yielded “razor” results—between 150 and 225 grams—after each test. Both models can be used to sharpen all manner of kitchen knives, including serrated knives, as well as hunting, filet, and pocket knives.

They worked quickly. On both models, it took us a maximum of 4 minutes, from start to finish, to bring an 8-inch knife from a sandpaper-dulled state to a like-new edge. Following the instructions, we found that every “pull” of an 8-inch blade through the sharpeners took between 5 seconds (on the coarse abrasive) to just 1 or 2 seconds (on the fine “stropping/polishing” abrasive), and the total number of pulls topped out at around 30, making the process a breeze.

They are intuitively designed and easy to use. One reason these models produce consistently sharp knives is their design, which removes any guesswork and makes it virtually impossible to mess up the sharpening process. Most electric sharpeners use rigid, angled slots to help orient the blade. But for these two sharpeners, the company added a feature that other models lack: spring-loaded guides inside the slots that grip the blade and keep it from shifting during the sharpening process. This ensures a consistent angle for a reliably sharp edge.

They are built to last. Both the 1520 and the Trizor 15XV are heavy, sturdy pieces of equipment, weighing 4 pounds 2 ounces, and they’re equipped with relatively quiet motors. Each has a footprint of about 2.5 square feet, so they don’t take up a lot of counter space and can be easily stashed away when not in use.

Both models also feature a handy “diamond cleaning system,” which removes debris from the Stage 3 polishing/stropping disks with an easy flip of a switch on the back.

The Trizor 15XV has proved its longevity: Our 2016 test model Trizor 15XV has stood up to years of use in the Wirecutter kitchen. Neither unit is cheap, but if you use your knives often, we believe these sharpeners are a worthwhile investment.

The 1520 is especially versatile. If the angle of your knife is important to you, the 1520 has the slight advantage over the Trizor 15XV because it can sharpen at either 15 or 20 degrees. (The Trizor 15XV sharpens at a 15-degree angle only). Since the 1520 is only slightly more expensive, we think the versatility of two angles is worth the extra investment. Otherwise, we find these models to be equivalent in their excellence.

Flaws but not dealbreakers

They’re expensive. The Chef’sChoice sharpeners are certainly an investment, but we think they’re worth it because of their speed, convenience, and longevity.

They’re a little bulky. Though they’re not as big and unwieldy as some of the sharpeners we tested, the Chef’sChoice 1520 and Trizor 15XV are not as easy to stash away as our budget pick, the Work Sharp E2, or other styles, like rolling sharpeners.

They shave away some metal from the knife’s edge. While we didn’t see any alarming amounts of metal removed during our testing rounds, we did notice that these models were capable of shaving away a little more material than whetstones or rolling sharpeners would. That said, the spring-loaded guides on our picks ensure precision and efficiency, so the sharpeners are removing just enough material to reveal a sharp edge.

If you’re not planning to sharpen a lot of knives at once, and if you don’t mind giving your knives a quick pull more frequently (before they get dull), the Work Sharp Culinary E2 is a fraction of the price of our picks, and it’s also more compact. It’s not nearly as powerful as the Chef’sChoice 1520 or the Trizor 15XV, and it’s not nearly as fast. But it produces a good enough edge, one that’s notably better than edges produced by other similarly priced sharpeners we tested.

It's small and simple. The E2 is the smallest and simplest of Work Sharp Culinary’s models. Like its “big brother,” the Work Sharp E5-NH (see the Competition), the E2 lacks the Chef’sChoice models’ spring-loaded guides in the sharpening slots, so you have to keep the knife aligned yourself. But due to the E2 sharpening slots’ simple design, this is fairly easy: Their sides are parallel, and the gap between them is small, so you really can’t horribly misalign the blade.

It renders an acceptable sharpness to all types of knives. Sharpening with the E2 took a long time, almost 10 minutes, compared with about 4 minutes with the Chef’sChoice sharpeners. But in all fairness, this sort of sharpening—where you take a completely ruined edge and create a brand-new one—is usually a once-in-a-knife’s-lifetime operation.

Thereafter, if you take reasonable care of your knife, a quick touch-up every few months will be enough. That’s the sort of sharpening the E2 is best suited to. During our testing of severely dulled knives, the E2 was able to restore the edges to an acceptable sharpness of about 400 grams, as read by the sharpness tester. The Work Sharp worked well enough for the knives to slice through tomatoes without too much effort, but it didn’t get the knives as sharp as our top picks did.

Like our top picks, the E2 can also sharpen serrated knives, and it has the extra bonus of being able to sharpen scissors.

Its auto-shutoff feature slows down the process. The E2 suffers from one irritating shortcoming: It has a built-in timer that shuts it off after 50 seconds of sharpening (40 seconds on the fast, “reshape” speed and 10 seconds on the slow, “sharpen” speed). This is meant to keep you from over-sharpening a knife. But in practice, it’s not enough time to resharpen even a small paring knife, and it’s not nearly enough time to reshape a very dull chef’s knife. And so you wind up repeatedly turning the machine back on, cycle after cycle, until your knife is sharp. To get a good edge from a sandpaper-destroyed one, it took us about 10 minutes and 50 “pulls” through the E2’s abrasive wheels (25 pulls of 8 seconds each per blade side, plus the time it took to check and reset the blade between pulls).

We found that for a blade dulled by normal kitchen use, it required 10 to 14 pulls, or a total of 3 to 5 minutes, to be sufficient. If you’re using this sharpener regularly to maintain your blades, the auto-shutoff feature should be much less frustrating.

Honing rods (also known as honing steels, knife steels, or sharpening steels) are not technically sharpeners, though they’re often mistaken as such. Rather than removing metal to reveal a sharper edge, as knife sharpeners do, they simply help keep a blade’s edge keen by straightening out the tiny dings and dents caused by everyday slicing and chopping.

Between sharpenings, we recommend that you use a honing rod. Honing is a simple and fast process—it takes just a few seconds—and it can extend the life of a sharp edge for weeks or even months. For that reason, we consider them an essential tool for cooks. (Check our guide to chef's knives for tips on how to use a honing rod.) In a testing of honing rods, we found that the Idahone Fine Ceramic Sharpening Rod (12 inches) stood out for its exceptionally smooth surface, which was gentle on the blades of all types of knives.

This style of sharpener has become a social media darling. It usually consists of a magnetic block, which holds your knife at the proper angle, and it’s paired with a cylinder that you roll against the blade. These sharpeners purport to be much easier to master than whetstones: Just choose your angle, snap the blade onto the magnet, and start rolling.

It sounds promising, but we tested three rolling sharpeners—the Tumbler, the HORL 2, and the Work Sharp RKS—and we found issues with safety, consistency, and potentially painful repetitive motions.

We did like that they were all compact and easy to store, as well as that they were able to sharpen knives at multiple angles. But in the end, the only one we would consider recommending is the Tumbler. It had the strongest (and therefore safest) magnet. And even though using it took some time and elbow grease, it produced a sharp edge from sandpaper dullness. It’s also typically the least expensive of the three we tested.

Overall, we found the Tumbler occupies a nice middle ground for those wary of electric sharpeners and those reluctant to learn proper whetting. Still, due to the safety and accessibility concerns mentioned above, we weren’t confident about making any rolling sharpener an official pick. We plan to continue using and evaluating the Tumbler for future updates.

If you do want to take the leap into sharpening your knives by hand on a stone, we recommend water stones, and not oil stones. They’re easier to master and less messy. And, as the name suggests, they use water as a lubricant, so to clean them, you simply rinse them under the tap when you’re done sharpening.

You’ll need two stones of two grits: a relatively coarse one, for setting the edge, and a fine one, for polishing it. A longer stone is easier to use, so we recommend 8-inch versions. The 1000/4000-grit combination stone from Norton is a great way to start out without breaking the bank, and it comes with a stand that keeps your knuckles from bumping into the counter when you’re sharpening.

There are many different ways to sharpen with water stones, and you can find them all on YouTube. It gets bewildering, so be ready for a learning curve, along with a lot of prep, labor, and mess. Knife forger Chelsea Miller warns, “You can do more damage than good to your knives unless you spend quite a long time practicing using a whetstone to get it just right.”

We trust the method recommended by Stella Culinary as a solid way to get started.

This is not a comprehensive list of everything we tested in previous iterations of this guide, just what’s still available.

Electric knife sharpeners

We liked the compact size, lightness (about 1 pound), and portability of the Chef’sChoice Rechargeable AngleSelect DC 1520. It stands apart from other electric sharpeners because of its rechargeable battery, which means it can be operated unplugged. Like the Chef’sChoice 1520, this model sharpens Asian and European knives at 15- and 20-degree angles. But unlike the motors on its Chef’sChoice siblings, this model’s motor is very loud, and it didn’t yield quite as sharp an edge as our picks.

The Ken Onion Edition Knife & Tool Sharpener MK.2 comes with a QR code for watching a demo, which is absolutely necessary in order to figure out how to work it. This model features seven speeds, and it has five belts, since it can go beyond the kitchen—it can also sharpen axes and tools. Because of the studying involved, and because this feels more like a garage tool than a kitchen tool, we considered it less user-friendly than the other sharpeners and more than the home cook needs.

We found the Tormek T-1 Kitchen Knife Sharpener to be heavy, bulky, very expensive, and unable to get the knives nearly as sharp as our picks.

We were excited about the compact design of the Smith’s Mesa Diamond Adjustable Electric, and we liked that it featured adjustable angles and was extremely easy to use. After several tests, however, it would not significantly sharpen a dull knife.

The budget-friendly, three-slot Smith’s Deluxe Diamond Electric Knife Sharpener promises to sharpen straight and serrated blades, plus scissors. However, compared with our budget pick, the Work Sharp E2, this model took much longer to render an only somewhat acceptably sharp edge.

The Work Sharp Culinary E5-NH is capable of making an edge as sharp as the Chef’sChoice 1520 and the Trizor 15XV. But it lacks spring-loaded guides that align the blade—you have to carefully hold the knife against the slot’s sidewall. Unlike those of the Work Sharp E2, the sides of the slot are not parallel, and if you slide the knife along the wrong side, you’ll be sharpening at an incorrect angle. Like the E2, the Work Sharp E5-NH has an automatic timer function that’s more of a hindrance than a help: It shuts off the machine every couple of minutes, often in the middle of a sharpening session.

The Chef’sChoice ProntoPro 4643, a former pick, costs about the same as the Work Sharp E2, but it produces a coarser edge. The E2 makes a finer edge that cuts more smoothly and with less effort.

The well-reviewed McGowan Diamondstone Electric Knife Sharpener rendered a very nice edge. It also threw off an alarming amount of dust, indicating that its grinding wheels were rapidly wearing down. Along with that, the lightweight motor made us skeptical of its long-term performance, despite a limited three-year warranty.

The electric Presto EverSharp 08800 gets great reviews. In our test, though, its flimsy motor instantly bogged down when our knife contacted its sharpening wheels—even light pressure threatened to stop the sharpening wheels entirely. The high, wide guide frames meant it couldn’t sharpen the last ¾ inch of a blade, an unacceptable shortcoming.

Manual knife sharpeners

The Mueller UltraSharp Diamond 4-stage Manual Knife Sharpener was the only model that rendered our knives even duller.

At first, the Cangshan Professional Knife + Scissor Sharpener, 3-Stage Adjustable 14-24 Degree, 1026108 seemed like it could be a great budget contender, returning dull knives to sharp after an initial round of testing. But it did not perform as well on subsequent tests, which caused us to believe that the carbide wore down after just a few uses.

The Brod and Taylor Classic VG2 is easy to misuse, which means blades could get damaged. When used correctly, it can quickly produce a sharp, honed edge. But a slight error in the angle at which you’re holding the knife can create an uneven bevel or strip away too much metal from the blade.

Rolling knife sharpeners

The HORL 2 is conveniently compact and has an attractive walnut finish. But the magnet was not strong enough to keep knives in place while sharpening; this caused the knife to flop and made it difficult to maintain a consistent angle. Narrower knives tended to slip off the magnet, too.

The Work Sharp Rolling Sharpener was the most ergonomic of the three: In lieu of a fully cylindrical shape, it has a “soft touch grip” and rolls on mini wheels. But its weak magnet caused the knife to become easily dislodged.

An extra ⅛ inch of magnet on the Tumbler kept the knives the most stable of the three rolling-style models we tested. We also found the Tumbler to be the most effective rolling knife sharpener. We plan to continue testing the Tumbler and other rolling-style models for future updates.

This article was edited by Marilyn Ong and Marguerite Preston.