Best Ninja Knife Sharpener: NeverDull and Orange Ninja Options

All three picks are manual, so none needs a plug. The real differences are which knives each one accepts, whether you are buying knives too, and where it lives between uses.

We judged each sharpener on four things: whether it fits the knives you own, how easy the routine is to repeat, where it lives between uses, and how much upkeep it asks for. Our star ratings come from that fit-and-effort assessment. They are editorial scores, not lab measurements, and they are not borrowed from any retailer.

We weighed each sharpener against the manufacturer's stated routine, the knives it is built to accept, and how it holds up as a drawer or countertop fixture. Where we judge feel and convenience below, we say so plainly, and where a detail could not be verified for a model, we flag it.

Compatible knives and sharpening system

The K31300 works on compatible Ninja straight-edge knives and excludes serrated knives and shears. Use it upright with clean, dry knives. Start and finish with the slider down, seat the blade in the right opening, and hold the grip. When you finish, release the knife with the button, then rinse and dry it.

The manufacturer's routine is to sharpen daily-use knives every 2 weeks. Never force a jam, and never store knives inside the unit.

Reasons to choose it and limitations

The standalone format is the draw. It spares you from replacing knives you already like.

Its compatibility limit matters: it cannot sharpen a bread knife or a non-Ninja chef's knife from the same drawer. Treat the warranty with care too: the 10-year limited warranty is not a promise that the abrasive wheel will last a decade without replacement.

What you get with the built-in sharpener

The 17-piece count includes the knives, shears and the block itself, so it does not mean 17 knives. The set holds chef, bread, slicing, santoku, boning, utility and paring knives, eight steak knives and kitchen shears. The blades are German stainless steel with ergonomic handles.

The sharpener is a lever-operated wheel built into the countertop block. A full lever stroke matters: the wheel needs to travel along the whole blade instead of working one short area. The block keeps blades snug in storage, and its suction feet steady the base while you sharpen.

The mechanism is meant for clean, compatible straight-edge Ninja knives. The serrated bread knife and the shears are excluded, and you should rinse sharpening residue off the blade before you prepare food.

When buying a complete set makes sense

A full set makes sense when you are starting over or retiring a drawer of odd knives.

It makes less sense if you already own good knives. The block takes noticeable counter space, and the set contains more specialty blades than everyday prep usually needs. Hand-washing adds a cleanup step when the rest of your tools go in the dishwasher. The total outlay is also the highest of the three picks, which is why it ranks second.

Supported blade types and sharpening stages

Sharp Pebble lists chef, paring, bread, steak, fillet and serrated knives as supported. Straight-edge blades use the coarse, medium and fine positions as needed. Serrated blades go through the dedicated serrated position instead of the straight-edge progression.

Pull the knife through in one direction. Do not saw it back and forth.

Reasons to choose it and limitations

It covers more of the average knife drawer than any NeverDull product, it fits in that drawer, and it is the cheapest pick here.

The limitations are real. Its fixed sharpening geometry means you should check that your blades fit before relying on it. Sharp Pebble's own descriptions of the coarse and medium abrasives are inconsistent, so follow the labels and instructions that come with your unit rather than a universal coarse-to-medium order. We also would not assume it sharpens scissors: no model-specific approval exists, and Sharp Pebble sells a separate scissor sharpener.

For owners of Ninja knives

Start with NeverDull: the K31300 if you only need to keep your knives sharp, the K32017 if you are also replacing knives and storage. We could not verify compatibility across every Ninja knife generation, so check your model.

For shoppers considering Orange Ninja sharpeners

Orange Ninja is a Sharp Pebble product, so it has no official tie to SharkNinja. Choose it when you want one sharpener for a mix of brands, or when you need a serrated option.

Knife compatibility, edge type and sharpening angle

Check your blade types first. We could not establish exact sharpening angles or grit ratings for these three picks, so do not assume they suit single-bevel or ceramic blades.

Electric, mini and adjustable-angle sharpeners also exist. Sharp Pebble sells a mini coarse and fine model, an adjustable-angle system and an electric rolling sharpener. They are separate products, so their angle controls and power do not describe the Orange Ninja four-stage tool. We left them out of our picks.

Standalone sharpener or complete knife set

If you like your current knives, buy a standalone sharpener. If your drawer is a mismatch of dull blades, a set can make sense.

Ease of use, storage and total cost

Guided systems like NeverDull reduce guessing. Pull-through tools like Orange Ninja are quick but rely on a steady pull. For storage, the standalone NeverDull and the Orange Ninja go in a drawer.

On cost, think in tiers. The Orange Ninja is the budget pick, the K31300 is mid-priced, and the K32017 is the premium option because it includes a complete set of knives.

Follow the instructions for your exact model

Use the instructions packed with your unit. For the K31300, that means clean, dry knives, an upright sharpener, and 10 full slider strokes for maintenance. For the K32017, use a full lever stroke so the wheel travels the length of the blade.

For Orange Ninja, follow the labels on your unit and check the supplied care sheet before cleaning.

Cleaning, storage and signs of wear

Under the recommended NeverDull routine, clean the wheel every 6 months. Rinse it, brush it softly and dry it immediately. Replace the wheel every 2 years, keep its pin, and check that it rotates freely. Damp-wipe the housing with soapy water and keep it away from heat.

Hand-wash the K32017 knives and dry them right away. If a blade stops cutting cleanly after a normal session, or the wheel catches, treat that as a sign it needs cleaning or replacement.

For a drawer of mixed knife brands that includes a serrated bread knife, the Orange Ninja beats both NeverDull options: it covers the collection with one compact tool at the lowest cost. The K32017 only wins over the K31300 when your current knives are already worn out, because then the block replaces two purchases with one. If neither describes you, the standalone K31300 is the simplest way to keep the knives you have sharp.