Descriptions:

Boning knives are commonly used specifically for removing bones from meat while fillet knives are commonly used for removing bones and skin from meat, especially fish.  There is some overlap as boning knives can be used for filleting and there are some all-purpose, boning/fillet knives.

Our Boning knives have a thinner blade than most other kitchen knives but they typically aren’t as thin as fillet knife blades, and are not necessarily flexible.  The blades of fillet knives sometimes curve upward while the blades of boning knives are usually straight.  This makes boning knives better for larger and tougher meats like pork, beef or chicken, as boning knives are sturdier and thicker than fillet knives.