They officially debuted on February 14, 2019, with the studio album V.[4] The members of Vanner—Taehwan, Gon, Hyesung, Sungkook, and Yeonggwang—were trainees for an average of five years.

[6] The group also started a crowdfunding support project which achieved over 250% of the target amount reflecting a global fandom even before their official debut.

[7][8] On February 14, 2019, the group officially debuted upon the release of their studio album V and its lead single "Better Do Better," as well as appeared on Mnet's music show M Countdown for the first time.

[24][25] As part of the top 6 and the final winning team, Vanner performed in the Your Time concert tour in Seoul on May 5 to 7 at Jamsil Indoor Gymnasium,[26] Busan on June 24 to 25 at KBS Busan Hall,[27] Taipei, Taiwan on July 15 at Taipei International Convention Center,[28] Hong Kong on December 9 at Kowloonbay International Trade & Exhibition Centre,[29] and encore performances at Korea University's Hwajeong Gymnasium from July 22 to 23[30] and Kaohsiung Arena in Kaohsiung, Taiwan on November 25.

[33] On August 21, Vanner returned after winning Peak Time and released their first mini album Veni Vidi Vici.

The group held their showcase at Yes24 Live Hall, where they presented their lead single "Performer" and Monsta X's Hyungwon-produced song "Want U Back".

[34] The EP topped the iTunes Global Album Chart in the Philippines, Hong Kong, and Taiwan and ranked second, fourth, and ninth in Brazil, Italy, and the Netherlands, respectively.

[41] Furthermore, Vanner attended and performed at the 5th Newsis Korean Wave Expo on August 23, where the group was honored with the "Next Generation Hallyu Star Award".

[56] A couple of weeks prior to their comeback, the band dropped their first English single, a cover of Charlie Puth's "I Don't Think That I Like Her", on September 13.

The single achieved top positions in several iTunes charts in Hong Kong, Taiwan, Canada, Malaysia, Poland, and the Philippines.

The band hosted a showcase during which they performed tracks from their EP, including their lead single "Automatic", as well as previously introduced songs from their concert, "Be Together" and "New Heights", and "Blossom", a piece written and composed by Highlight's Lee Gi-kwang.

[60] On October 17, KLAP Entertainment announced that Hyesung would begin his mandatory military enlistment on November 4 and serve as an active-duty soldier, similar to his fellow member Sungkook.