Outdoor extension cords vs indoor extension cords: Outdoor cords are built for safety and durability, indoor cords are a fire risk outside

The key difference is internal wiring and features, not just the jacket. Outdoor cords use heavier gauge wire (lower AWG) to prevent voltage drop over distance, have molded or sealed plugs for moisture protection, and are always grounded. Indoor cords use smaller wire, are often ungrounded, and lack moisture seals. The jacket material also differs — outdoor cords use rubber or heavy vinyl that stays flexible in cold and resists UV, while indoor PVC gets brittle. Using an indoor cord outdoors is a short circuit waiting to happen.