Usually sporting shoulder-length hair, the photo showed Chrissy with her stunning waves cascading down, almost reaching her stomach.
Click on the image below to see Chrissy's old hairstyle
The 28-year-old revealed that she has had hair extensions put in to her already gorgeous locks, making them dramatically longer. "Oh my god I did it," she captioned the photo, sharing her excitement with her 940,000 followers. "#extentionslife #iamaboutthislife thank you @priscillavalles @giannandrea1."
It's not the first time the stunning model has wowed her fans on Instagram. Following her wedding to singer John Legend in September 2013, Chrissy stunned fans when she unveiled the three breathtaking Vera Wang gowns she wore for the ceremony in Lake Como, Italy.
Since then the couple have often shared photos on the social media app of their cosy nights in and home cooked meals, as well as updates on their three bulldogs, Puddy, Pippa and Penny.
The couple teased fans when they announced they had bought Penny, at a first glance making it seem like a pregnancy announcement.
"NEW FAMILY MEMBER ALERT!!" tweeted Chrissy. "She is our new little tripod lovebug," she then added, revealing it was a joke. "Yes. She has 3 legs WHICH IS MORE THAN YOU OKAY".