For a garage door opener circuit, the safest and most common choice is standard building wire for the permanent wiring in the wall or ceiling, not a flexible appliance cord. In most homes, the opener is simply plugged into a ceiling receptacle, and that receptacle is fed by normal branch-circuit wiring sized to the breaker and receptacle rating. If you are asking about the wire that feeds the outlet, that is usually 14 AWG copper on a 15-amp circuit or 12 AWG copper on a 20-amp circuit, depending on what the circuit is designed for and what your local electrical code allows.
If the opener itself comes with a factory cord and plug, leave that intact. The opener is generally treated like an appliance, so the hard-wired part is usually the branch circuit and the outlet, not custom wiring directly into the motor. Using the manufacturer’s cord is the cleanest setup because it’s already matched to the unit’s current draw, grounding, and strain relief. Replacing that cord with something improvised is where people get into trouble.
If you are installing a new receptacle in the ceiling for the opener, use cable rated for the environment and run it through proper boxes and fittings. In a typical finished or framed garage, NM-B cable is often used where allowed, but garages can have exposure, damage, or local code rules that change the answer. If the wiring is exposed on the surface, in a damp area, or subject to physical damage, you may need conduit with individual conductors such as THHN/THWN instead. That detail matters more than the opener itself.
Do not use light-duty extension cord wire as a permanent solution. It can overheat, loosen at connections, and fail when the opener starts and stops repeatedly over the years. Also, avoid undersized wire, especially if the opener shares a circuit with outlets or lighting. A garage door opener does not usually draw a huge amount of power, but the correct wire size still needs to match the breaker and the installation method.
A practical setup many electricians use is a dedicated ceiling receptacle on a properly protected branch circuit, with the opener plugged in using its original cord. If you want battery backup or smart controls, the wiring still does not usually change much; the main thing is having a solid, grounded receptacle and a code-compliant circuit. If you are not sure whether your garage conditions call for NM cable, conduit, or a dedicated circuit, it is worth checking the local code or asking an electrician before you start.
