Apart from her group's activities, Choi has also starred in various television dramas such as The Third Hospital (2012), Dating Agency: Cyrano (2013), My Spring Days (2014), Squad 38 (2016), Man in the Kitchen (2017–2018), Tell Me What You Saw (2020), and most recently in Run On (2021), So I Married the Anti-fan (2021), If You Wish Upon Me (2022), and Not Others (2023).

She joined Echo Global Group and released her first solo single "Winter Breath" in 2018, before moving to Saram Entertainment in 2019.

[6] She later won first place at the 2002 Korea-Japan Ultra Idol Duo Audition and debuted in Japan as a member of Route 0.

In the early days, her acting work mostly involved several small roles and guest appearances—these include KBS2's sitcom Unstoppable Marriage (2007),[11] romantic comedy film Hello, Schoolgirl (2008),[12] SBS's drama Oh!

[14][15] During this period, musically, she recorded two songs—one trot song titled "KKok" with Girls' Generation member Yuri for the SBS' drama Working Mom, while the other one, "Feeling Only You", was a collaboration with Girls' Generation member Tiffany and South Korean duo The Blue.

[27] Park Ju-yeon from the Hankook Ilbo praised Choi for her lively character portrayal and said that there was not any "overdone emotions commonly appear in acting newcomers".

Her character is a terminally ill patient who gets a heart transplant; and meets her donor's husband, played by Kam Woo-sung.

[31] In 2015, Choi starred as the female lead in KBS2's special drama Perfect Sense, which was produced by Samsung Fire & Marine Insurance to help raise public understanding of the disabled.

[32][33] In June 2016, Choi starred as the female lead alongside Ma Dong-seok and Seo In-guk in the OCN crime drama Squad 38.

[51][52] On August 29, 2024, Saram Entertainment announced that Choi would be releasing her Japanese debut maxi single titled "Unstoppable" on October 30.

[57] In 2016, Choi launched a clothing brand called Beaming Effect with the aim to raise awareness for Retinitis Pigmentosa.

[60] Choi has also been appointed ambassador to the Korean Day of Overcoming Rare Diseases,[61] the Social Welfare Council and the National Disability Awareness Improvement Campaign.