Rapunzel's magic hair plays an extremely important and crucial part in the plot of Disney's Tangled''. Rapunzel's hair is what makes her special, glowing bright gold when she sings a special song known as "Healing Incantation." It is known to have the ability to heal the sick and wounded as well as return those who have died to life.
Rapunzel's hair is bright gold, and about seventy feet long. When cut, it turns brown. In the movie, when Rapunzel reaches the kingdom, four girls braid her hair with flowers.
At the beginning of the film, it is stated that the hair gets its power from a magic golden flower. This magic golden flower is used to heal the sick pregnant Queen of Corona, who gives birth to Rapunzel. Cells from the flower are passed into Rapunzel, making her hair glow and heal the sick just like the flower did. Mother Gothel, an evil old woman, who finds the flower before the Queen does, uses it to make herself young and beautiful. According to Flynn Rider, she has been using it for hundreds of years. When the queen uses it, Mother Gothel wants to get it back, so she breaks into the palace and cuts off a lock of Rapunzel's hair to keep for herself. However, the lock turns brown and loses its power. So she kidnaps baby Rapunzel to use the magic hair for herself. She raises Rapunzel as her own, deep with in a forest, in a hidden tower and will not let her leave the tower, for fear they will be seen together.
During Rapunzel's journey with a thief named Flynn Rider, Rapunzel's magical hair is used many times. Rapunzel used her magic hair as lighting to escape from the dark water and sing the "Healing Incantation" to heal Flynn's injury. This surprises Flynn greatly, prompting Rapunzel to explain the functions of her hair to him. At the end of the film, her hair is cut off, leaving it in a dark brown-colored pixie cut and initially unable to heal Flynn in its hair form. However, even in the end, the flower is unwilling to let him die and restores him to life with a tear.
In the TV series, Rapunzel's magic hair grows back to the length and color it was in the film. It grows back when Rapunzel and her handmaid, Cassandra, discover some mystical rocks with magical properties during a secret adventure. In the series, her new hair is revealed to be indestructible and cannot be cut. It's later revealed that Rapunzel's hair no longer possesses it's original powers to heal, but is revealed to have acquire a new power, protecting Rapunzel by creating a magical shield. It also appears to respond to her subconscious when she's dreaming because it was levitating all over her bedroom before she woke up.