As a part of a study abroad program, she went to Trinidad for an internship at a diplomat’s office and at a record label. While she was there, she sang backup for a friend’s band in front of over 80,000 people at the International Soca Monarch finals in 2002. According to Platten beginning in that moment she knew she had to pursue music full-time.

Platten graduated from Trinity College with a degree in political science in 2003. She moved to New York City’s Greenwich Village performing in a Prince and Sly and the Family Stone cover band called Dayz of Wild. She performed her solo music around the Village and eventually began touring the country.

On July 31, 2010, Platten married Kevin Lazan in a Jewish ceremony. In July 2018, Platten announced that they were expecting their first child, a girl. Platten gave birth to their daughter Violet Skye Lazan on January 26, 2019.

Her first album, Be Here was released from Rock Ridge Music in 2011; due to the 2003 album Trust in Me is not on the album. Her 2011 single “1,000 Ships” peaked at number 24 on the US Billboard Adult Top 40 chart, also playing at various radio stations. An earlier song, “Seven Weeks”, was used for the film The Good Guy. The theme song for ABC Family’s Jane by Design, “Work of Art” was performed by Platten on hire. Her song “Begin Again” was used in the hit ABC Family TV show Pretty Little Liars 100th episode “Miss Me x 100”. Her song “Don’t Care What Time It Is” was used in VH1’s Basketball Wives. Her song “You’re Safe” was used in MTV’s Finding Carter in September 2014. On June 27, 2014, Platten debuted “Fight Song” on the music social network We Heart It as part of an artist spotlight.

On February 19, 2015, Platten released “Fight Song” from Wildfire. The song has been used in various media and it was the official anthem for the 2016 Democratic presidential nominee Hillary Clinton. It reached number six on the US Billboard Hot 100, number two on the Australian Singles Chart, number six in Ireland, number eight in New Zealand, number nine on the Billboard Canadian Hot 100 and number one on the UK Singles Chart. It has quintuple platinum sales in the US. Platten’s 2015 Fight Song EP reached number 20 on the Billboard 200.

Platten served as a support act on Alex & Sierra’s and Andy Grammer’s “The Good Guys & A Girl Tour” in early 2015. She then toured with Colbie Caillat and Christina Perri on their “Girls Night Out, Boys Can Come Too Tour” throughout the summer of 2015.

On September 11, 2015, Platten released second single named “Stand by You” from Wildfire. It has peaked in the top ten on charts in Canada and the United States, and has peaked in the top twenty on charts in Australia and Poland. The song has since been certified Platinum in the United States.

In October 2016, Platten sang The Star Spangled Banner prior to Game 1 of the 2016 World Series between the Cleveland Indians and Chicago Cubs.

In 2017, Platten served as an opening act for two Los Angeles shows and one Las Vegas show on Faith Hill and Tim McGraw’s Soul2Soul: The World Tour.

“Broken Glass”, the lead single from her fourth studio album, Waves was released on August 18, 2017. The album was released on October 27, 2017.

In 2018, Platten was the main musical act at the Boston Pops Fireworks Spectacular. Along with performing her singles “Stand By You”, “Better Place”, and “Fight Song”, she also reminisced about her childhood in Boston.