On “8 Letters,” Why Don’t We talk about a phrase containing eight letters, which was later confirmed as the phrase “I love you”. The song serves as the third single and title track from Why Don’t We’s debut album.

The track became the band’s first to hit one-hundred million streams on Spotify, and did so on April 7th 2019.
Just a month later, the track also became their first single to be certified gold by the RIAA – moving over 500,000 units within nine months.

The song is about being scared of falling in love with someone new, trusting them, and finally saying those eight letters despite previous heartbreak. The song shares a similar meaning with a previous Why Don’t We song, “Runner”, albeit being told from the opposite perspective.