Salt-free dyeing aims to decrease the environmental impact during the dyeing process and targets moving towards an eco-friendly and sustainable dyeing process. It is an eligible, more impactful way of minimizing salt discharge into water and conserving water as much as possible. The materials used for salt-free dyeing are cotton or modified cotton fabrics that contain cellulosic groups, which aid in the fixation of salt. Cationization plays a key role in this method as it turns the negative parts of the cellulosic groups into positive parts, which are more strongly bonded with the negative parts of the reactive dyes. The more the positively and negatively charged molecules in the medium, the faster the fixation rate will increase. It can also be regarded as an alternative dye fixation method of reactive dyes. Cationization improves characteristics such as color fastness, strength, uniformity, absorption, and fixation. This paper aims to provide a critical overview of the cationic process of the salt-free dyeing process in different fabrics. The salt-free dyeing methods are thoroughly discussed, and various dyeing properties and enhancements for different fabrics are comprehensively analyzed.