What is the gas in a light bulb made out of?

The gas inside a standard incandescent light bulb is typically an inert gas, such as argon or a mixture of argon and nitrogen. These gases help to prevent the filament from oxidizing and burning out quickly when heated. In some compact fluorescent and LED bulbs, other gases or materials are used to produce light, but traditional incandescent bulbs mainly utilize these inert gases for efficiency and longevity.