A switchblade is a type of pocketknife that has a sliding or pivoting blade contained in the handle which is extended automatically by a spring when a button, lever, or switch on the handle or bolster is activated. It is also known as an automatic knife, pushbutton knife, ejector knife, flick knife, stiletto, flick blade, or spring knife. The key features of a switchblade include:

• Blade: The blade is spring-loaded and opens automatically when a button or switch on the handle is pressed.

• Types: There are different types of switchblades, including side-opening or out-the-side (OTS) knives, which resemble traditional manually-operated folding knives, and the double action out the front (DAOTF) switchblade, where the blade comes out at the top of the handle like a pen.

• Legality: The legality of switchblades varies by state and country. In the United States, the Federal Switchblade Act outlines how knives are treated in regard to commerce and across state borders, and what qualifies it to be a switchblade. Any automatic knife that opens automatically, either by a button, inertia, or gravity, is a switchblade knife. In some states, switchblades are illegal to own or carry, while in others, they are legal with certain restrictions.

Switchblades are often used for self-defense due to their ability to be carried discreetly and deployed quickly. However, they have also been used for nefarious purposes by criminals.