* Formed in 1995 in Des Moines, Iowa
* Known for their aggressive and heavy sound, as well as their distinctive masks
* Has released six studio albums, with their latest, We Are Not Your Kind, being released in 2019
* Has sold over 15 million albums worldwide
* Has toured extensively throughout the world and headlined major festivals such as Ozzfest, Download Festival, and Knotfest
Metallica
* Formed in 1981 in Los Angeles, California
* One of the most successful and influential heavy metal bands of all time
* Has released 10 studio albums, with their latest, Hardwired...to Self-Destruct, being released in 2016
* Has sold over 125 million albums worldwide
* Has toured extensively throughout the world and has played over 2,500 concerts
* Has won numerous awards, including nine Grammy Awards and two American Music Awards
Popularity
* Slipknot has a dedicated and passionate fan base, but their popularity is perhaps more niche compared to Metallica.
* Metallica, on the other hand, has a wider mainstream appeal and has been able to attract a larger audience.
* This is reflected in the sales figures, with Metallica having sold over 10 times more albums than Slipknot.
Ultimately, it is difficult to say definitively which band is more popular. Both bands have their own strengths and weaknesses, and their popularity can vary depending on the region or country. However, based on the evidence above, it is clear that Metallica has a larger overall following and is more well-known around the world.