Azo dyes, including Tartrazine, Sunset Yellow, and Carmoisine, are added to foods to provide color, but they have no value with regard to nutrition, food preservation, or health benefits. Because of their availability, affordability, stability, and low cost, and because they provide intense coloration to the product without contributing unwanted flavors, the food industry often prefers to use synthetic azo dyes rather than natural colorants. Food dyes have been tested by regulatory agencies responsible for guaranteeing consumer safety. Nevertheless, the safety of these colorants remains controversial; they have been associated with adverse effects, particularly due to the reduction and cleavage of the azo bond. Here, we review the features, classification, regulation, toxicity, and alternatives to the use of azo dyes in food. •The availability, affordability, stability and safety of azo dyes make them desirable for food use.•Tartrazine, Sunset Yellow or Carmoisine are the most widely used azo dyes due to their coloring capacity.•The safety of these artificial colorants is controversial due to possible adverse and toxic effects.•Further research on these dyes is needed to provide consistent data, alternatives to their use and safety.