"Party 4 U" began to resurge in popularity and
streaming in February2025 after
going viral on the online video platform
TikTok, where users posted videos of themselves singing the song's second verse. As a result of the resurgence, US on-demand streams for "Party 4 U" more than doubled from January to February 2025, according to
Luminate Data. On 19February, the track entered the US
Spotify Viral 100 chart at number 80, marking the highest new entry. In response, Charli XCX
tweeted, "It's p[retty] crazy that this song is suddenly getting love in this kinda way. I know this song means so much to so many [fans]". Atlantic Records released "Party 4 U" as a single to
contemporary hit radio in the United States on 13May2025. A
7-inch vinyl of the song, featuring an
etched B-side, was released on 18April2026, as part of
Record Store Day. "Party 4 U" peaked at number 42 on the
Billboard Global 200 chart dated 31 May 2025. It reached the national charts of Ireland (8), Singapore (12), the United Kingdom (19), Australia (25), Canada (46), and the United States (55). The track also peaked at number 7 on the
Sweden Heatseeker chart, number 13 on
Billboard Philippines Hot 100 chart, number 14 on
IFPI's
Official Philippines Chart, number 17 on the
Malaysia International chart, number 71 on the
Lithuania Airplay chart, number 88 on the
Greece International chart, and number 121 on the
Portuguese Singles Chart. "Party 4 U" received platinum
certifications in Canada from
Music Canada and in New Zealand from
Recorded Music NZ, as well as a gold certification in the United Kingdom from the
British Phonographic Industry. ==Music video==