It was composed by Taylor with her regular writing partners, Max Martin and Shellback.
Taylor told Alan Carr on Chatty Man, that she was inspired to write the song as a way of dealing with some of the gossip she was reading about herself.
She read somewhere that she was supposed to have a treasure chest of ex-boyfriends' belongings, which she has to go and touch in order to write songs. It is well known that she has used some of her ex-boyfriends as inspiration for her material.
Taylor said, " I've had every part of my life dissected - my choices, my actions, my words, my body, my style and my music. When you live your life under that kind of scrutiny, you can either let it break you or you can get really good at dodging punches. Then when one lands, you know how to deal with it. And I guess the way that I deal with it, is to shake it off."
So she wrote 'Shake It Off' as a kind of coping mechanism for when people say hurtful things. She wanted it to be a song that helped other people who were feeling victimised too.
She said, "I wanted to be like, OK, you're irritated that I'm being myself. You're going to talk about me and make things up about me because I'm being myself so I'm just going to be myself even more."
'Shake It Off' made it into the UK singles chart in August 2014, peaking at NO. 2. By November 2014, it had sold 570,000 copies in the UK.
It was a No. 1 hit in 14 singles charts around the world and made the top 10 in 25 others.