At least 20ft, where the 1/4 plug goes in the wire is often bent at an angle and fails quickly there. As it's difficult to find longer cables like this I've actually only used one brand, then received a replacement, failed same place. Was thinking wrapping some electrical tape around that area to reduce the bend at that point (is for my child's headphone so he can sit on bed and watch his shows, room is 10ft wall to wall.)