"Good 4 U" (stylized in all lowercase) is a song by American singer-songwriter Olivia Rodrigo. It was released on May 14, 2021, through Geffen and Interscope Records, as the third single from Rodrigo's debut studio album, Sour (2021). The song was written by Rodrigo and its producer Dan Nigro who co-produced it with Alexander 23; Hayley Williams and Josh Farro were given co-writing credits due to influence from Paramore's "Misery Business" (2007). Musically, "Good 4 U" has been described as an upbeat song blending rock, pop, punk, emo, and alternative styles. It consists of a staccato bassline, energetic electric guitars, and explosive drumming, with lyrics addressing a former lover who moved on very quickly after a breakup. The song received acclaim from music critics, who praised the instrumentation reminiscent of the 1990s–2000s and Rodrigo's crisp songwriting. The accompanying music video features Rodrigo as a high-school cheerleader exacting revenge, visually alluding to the 2000s films Audition, The Princess Diaries, and Jennifer's Body. At the 64th Annual Grammy Awards, "Good 4 U" received a nomination for Best Music Video. The single reached number one in 23 countries including Australia, Germany, Canada, the United Kingdom, Ireland, and the United States; it was the second chart-topping single from Sour in many of those countries, following Rodrigo's debut single "Drivers License" (2021). "Good 4 U" peaked within the top 10 in more than 20 territories. The song received platinum or multi-platinum certifications globally and ranks among the top 100 most streamed songs of all-time on Spotify with over 2 billion streams as of November 2023.