The Brazilian Jiu-Jitsu is similar to the "kyu" and "dan" ranking system of Judo, and while it retains numeric ranking for "dan" or black belt ranks, it does not assign a numeric system to its "kyu" or lower ranks. Instead, below the level of a black belt, students are assigned a certain belt color, with different color sequences for children and adults. Additionally, adult belts are assigned white "stripes" on a black (or red) rank bar on the belt to denote progress within the belt, due to the large amount of time it typically takes to progress to the next belt color. Belts for children may either use a stripe system like the adult belts, or more recently, use a length-wise stripe in either white, unstriped, or black to signify progress within a given belt color.

Purple belt is the next adult belt rank after blue belt. By the time a Brazilian Jiu-Jitsu practitioner has achieved their purple belt, they not only are familiar with most areas of technique, they have also started to develop significant competency in many of them. They may still gravitate more to specific areas and strategies, with some areas still proving difficult to apply. Where a purple belt is competent, they will generally display more fluidity, better timing, and economy of movement than a blue belt would. By this time they also should have a significant theoretical understanding of many techniques well enough to be able to teach them to others.