Nilsen began a YouTube channel with the name Missglamorazzi on October 23, 2009, because she wanted to share her feeling of confidence with other people and push herself to overcome her fear of public speaking. She told herself to do something that scared her, and creating a YouTube channel fell under that category for her. In her videos, she covers topics such as fashion, lifestyle, and make-up.

In late 2014, Nilsen became a judge on the reality television show Project Runway: Threads. At the 2014 Teen Choice Awards and 2015 Teen Choice Awards, Nilsen was nominated for Choice Web Star: Fashion/Beauty.

Ingrid is of Norwegian descent on her father’s side and Thai on her mother’s side. On June 9, 2015, Nilsen uploaded a video on her YouTube channel, in which she came out as a lesbian.

From September 2015 to January 2016, Nilsen dated fellow YouTuber Hannah Hart. Nilsen has since begun a relationship with Erica Anderson. They announced their relationship on Instagram in 2018.

On January 15, 2016, Nilsen interviewed Barack Obama in a livestream hosted at the White House. She raised questions about the future of terrorism in the United States, taxation of feminine hygiene products, and discrimination against LGBT+ people. Nilsen also asked Obama to share the story behind an item of personal significance during the interview, to which Obama showed a series of small totems, stating each one reminds him “of all the different people [he’s] met along the way”.

In March 2016, Nilsen was named one of the United Nations Change Ambassadors to the intergovernmental organization along with six other female YouTube creators. The UN Change Ambassadors focused on the global fight for gender equality, one of the UN’s 17 Sustainable Development Goals established that year.

In July 2016, Nilsen, Do Something, and U by Kotex launched Power To The Period, the first nationwide period product drive. The campaign encouraged participants to run product drives for unopened tampons, pads, and panty liners that were then donated to local homeless shelters. As of September 2016, Power to the Period had donated almost 240,000-period products.

In October 2016, Nilsen was included on OUT magazine’s OUT100 list.

On December 4, 2016, The Trevor Project awarded Nilsen the Trevor Digital Innovator Award. “With a powerful social presence, Ingrid has used technology for the better and built a platform and voice to advocate for equality,” said Abbe Land, Executive Director and CEO of The Trevor Project. “She is a role model of her generation and truly is a beacon of hope. She continues to push boundaries and believes in the mission of The Trevor Project, making her the perfect fit for the award.”

In February 2017, Nilsen and Shiseido-owned bareMinerals announced a partnership, and Nilsen became the face of the brand’s two best-selling foundations. The partnership was one of the biggest deals between a beauty brand and an influencer to date.

In June 2019, Nilsen partnered with a nonprofit It Gets Better for a new campaign. Nilsen led #TheirStory campaign which asked LGBTQ+ members and their allies to share stories about inspirational figures via online videos. This campaign was covered on Instagram, Tik Tok, and YouTube. She attempted to raise $50,000.

On June 30, 2020, Nilsen announced through her Youtube channel she would no longer be uploading to YouTube.