chillhop or Lofi Hip Hop is a form of downtempo that combines elements of hip hop and chill-out music. It was popularized in the 2010s on YouTube and became an Internet meme.

In 2013, YouTube began hosting live streams, which resulted in 24-hour "radio stations" dedicated to microgenres such as vaporwave, a derivation of chillwave. Spotify added to the popular "lo-fi beats" wave by generating "Spotified genres", including "Chill Hits", "Bedroom Pop" playlists, and promoting numerous "chill pop" artists.

In 2017, a form of downtempo music tagged as "chillhop" or "lo-fi hip hop" became popular among YouTube music streamers. By 2018, several of these channels had millions of followers. One DJ, Ryan Celsius, theorized that they were inspired by a nostalgia for the commercial bumpers used by Toonami and Adult Swim in the 2000s, and that this "created a cross section of people that enjoyed both anime and wavy hip-hop beats". These channels equally functioned as chatrooms, with participants often discussing their personal struggles. By 2018, Spotify's "Chill Hits" playlist had 5.4 million listeners and had been growing rapidly.

Nujabes and J Dilla have been referred to as the "godfathers of Lo-Fi Hip Hop". Vice contributor Luke Winkie credited YouTube user Lofi Girl (formerly known as "ChilledCow") as "the person who first featured a studious anime girl as his calling card, which set up the aesthetic framework for the rest of the people operating in the genre" and suggested that "if there is one shared touchstone for lo-fi hip-hop, it's probably Madvillainy".

Viewership of lo-fi hip hop streams grew significantly during the 2020 COVID-19 pandemic. In April, MTV News noted, "there might be something to be said for lo-fi hip-hop's composition, and the way its creators mix simplistic melodies with a judicious use of words to create intense memories, feelings, and nostalgia" and stated that the quarantine in place in various countries "has led people to log more hours online due to boredom or virtual workplaces and schools, and livestreamed music performances are reaching their full potential".

Lo-fi hip hop is considered an Internet meme. Many producers in the genre later distanced themselves from the label or drifted into other music styles. Common criticisms of the genre included the music's simplicity and clichéd sound.