Fillet Knife vs Boning Knife – What Are the Differences?

Fillet knives and boning knives share similar shapes, cutting edges, and blade lengths. These similarities make it difficult to tell knives apart, leading to many people using them interchangeably. However, a closer look will reveal significant differences that make each knife unique in specific fields.

The key differences between fillet knife and boning knife are:

  1. Fillet knives are thin and light, whereas boning knives are thicker and heavier.
  2. The blade of a fillet knife features a pronounced curve, as opposed to the straighter boning knife blade.
  3. Fish fillet knife blades are as large as 11 inches, and the most common blade length for boning knives is between 5 to 7 inches.
  4. A fillet knife’s blade is more flexible than the usually rigid boning blade.
  5. Fillet knives are better for filleting delicate meats from fish, whereas boning knives are more suitable for deboning raw and tougher meats.

What Does a Boning Knife Look Like?

Boning knives are kitchen knives featuring a blade with a sharp point and narrow blade design. The blade is usually between 5 to 6-1/2 inches, or 12 to 17 cm in length. Stiff and flexible blades are available for different uses. A flexible boning knife is more suitable for poultry and fish boning, whereas stiff boning knives are better for beef and pork.

Some boning knife come with arched blades, which help remove fish meat from the bones with more precision. Since boning knives are not thick, making deep cuts, holes, and precise boning is easier.

What Does a Filleting Knife Look Like?

Fillet knife is primarily used for filleting and preparing fish. The blades are flexible and measure 6 (15cm) to 11 (28cm) inches long. Fillet knives feature trailing point blades, which are used to slice and skin fish meat. Trailing point has a back edge that curves upwards from the handle to the tip gradually, enhancing the knife belly. As a result, the knife makes quick and accurate cuts.

Another popular variation of fillet knives is the electric fillet knife. The blades are similar in size, but they attach to a motorized handle instead.

Electric fish fillet knives work similarly to reciprocating saws. The serrated blades move back and forth to cut through fish meat faster than the manual fillet knife. An electric fillet knife works via cord or Li-ion batteries, and the blades are detachable. While electric fillet knife is ideal for professional anglers and fish processing settings, anyone can get one.

Similarities Between Boning and Fillet Knife

A boning knife isn’t the same as a fillet knife. However, they share some similarities that often confuse people.

  • Both knives have thin blades with a prominent curve and share a similar length.
  • Boning knives and fillet knives come with straight or serrated cutting edges.
  • Manufacturers use similar materials to create boning knives and filleting knives. Primarily, you will find these two knives featuring stainless steel blades.

These visible similarities lead people to believe that a boning knife and filleting knife are the same thing. While you can use the knives interchangeably, knowing which knife you should use is essential if you value precise cuts.

Key Differences Between Boning Knife and Fillet Knife

Learn about the differences between a boning knife vs fillet knife to know which one to get depending on its intended use.


The biggest difference between a boning knife and a fillet knife is how you use them.

What is a fillet knife used for?

A fillet knife is good for turning a whole fish into fillets sliced with high precision. It can squeeze around bones and skin with ease to remove the meat with minimal damage or wastage.  

What is a boning knife used for?

The main purpose of a boning knife is to separate meat from the bone. Boning knives are used for slicing beef, chicken, or poultry. This type of knife is good for removing the silver skin you usually find in pork and lamb. It will also cut through muscle and connective tissue with ease.

Blade Shape or Design

Both knives share a similar blade shape, but some differences are noticeable upon closer inspection. Usually, boning knives are straight with a slightly curved and sharp point. This point serves a purpose, which is to pierce the meat. The curves of a boning knife are less prominent in boning knives.

Fillet knives have more pronounced curves going upwards, resulting in a curved point with a bigger belly. This design allows long and consistent cuts when you’re guiding the blade over the fish backbone. Unlike boning knives, a fillet knife doesn’t generally use a sharpened tip to pierce. All the work falls on the cutting edge, which often has serrations or scallops to remove fish meat close to the bone with less resistance.

Blade Length

Boning knives have blades between 5 to 6-1/2 inches long, whereas fillet knives are as long as 11 inches. Fillet knife blades are usually larger to let you use the full cutting edge in a back-and-forth motion. The smaller 6-inch fillet blades are ideal for smaller crappie or trout, whereas the larger 11-inch blade is more effective while prepping salmon or large tuna.

A boning knife is smaller for more precision while making deep cuts and holes. Smaller boning knives make delicate and tender cuts while deboning and removing skin from poultry. On the other hand, the larger boning knives are better for making thick cuts on beef and pork. They separate the meat from the bone while removing fat and connective tissue with ease.

Blade Thickness

Fillet knives have between 2.5-3.5 mm of thickness at the spine, whereas boning knives are usually 3/32 inches. This means that a boning knife is often thicker, heavier, and stiffer than a fillet knife.

The weight and thickness of a boning knife play in your favor. It allows you to apply more pressure to cut through ligaments or connective tissue without the blade budging. Simultaneously, the thin design of a fillet knife makes it possible to guide the blade through fish bones and meat with precision.


A fillet knife must be thin to offer flexibility and greater maneuverability. If the blade was stiff, it wouldn’t bend enough to make complicated cuts around rib bones. This problem would also complicate separating the meat from the skin after filleting the fish. The blade simply wouldn’t flex to accommodate the fish contour.

Boning knives must be thicker to avoid going off course when deboning thick and tough meats. Plus, they’re useful when you need to cut and separate wide sections. Flexible boning knives are thinner, and they’re more suitable for cutting at smaller angles. These are necessary if you want to avoid dealing damage to delicate meat pieces.

Can You Use a Fillet Knife as a Boning Knife?

The primary use for fillet knives is prepping fish. Since they’re thin and flexible, it wouldn’t be wise to use them as boning knives. You would encounter many issues, especially if you need to cut tough meat like venison or beef.

Should You Buy a Boning Knife or a Fillet Knife? Or Buy Both?

Consider buying a fillet knife only if you’re an avid angler or prep fish regularly. Otherwise, a boning knife is a more versatile option, allowing you to slice meat and prep small to medium-sized fish. If you deal with fish and meat frequently, then you will need one of each for better results.

When to Use a Boning Knife?

Use a boning knife when you need to cut beef, pork, lamb, poultry, or even saltwater fish. These knives separate meat while making intricate cuts around joints and bones to remove fat and connective tissue. The cuts will be tender and delicate, which are necessary when deboning and removing the skin.

When to Use a Fillet Knife?

Use a fillet knife if you prep fish regularly and want to save as much meat as possible. These knives are thin and flexible enough to remove scales and skin from the fish while adapting to the fish’s contour. As a result, filleting fish will be cleaner and more efficient.

My suggestion: Avoid using a fillet knife as a boning knife. Since the blades are flexible, they may snap under the pressure of cutting through tough meat.

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About Tom Hammaker

Tom Hammaker is a freelance copywriter with a specialty in advertorial blog posts. He’s worked with small local business owners and taken on larger projects with clients like Proctor and Gamble. He wrote his first direct marketing piece when he was a jobless teenager back in high school. It was a flyer for a landscaping business he was trying to start. The result? The mailing absolutely BOMBED! When he is not working, he's either out on the water fishing or playing golf. You can find him here on LinkedIn or his personal website

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