Background <p>Front-of-Pack Nutrition Labeling (FOPNL) is a promising public health measure to promote healthier food choices in the population. The present study tested the impact of the Nutri-Score and warning labels on purchasing intentions and product perceptions in Indonesia and Türkiye, where no FOPNL system is currently in place, and Mexico, where warning labels are mandatory since October 2020.</p> Method <p>Adult participants (<i>N</i> = 639; <i>n</i>_Indonesia = 212, <i>n</i>_Mexico = 203, <i>n</i>_Türkiye = 224) were randomly assigned to viewing eight product pairs (chips, instant noodles, meats, condiments, sweet spreads, cookies, yoghurt, fruit drinks) with either no label, a Nutri-Score, or warning labels, and indicated which product (or neither) they would rather buy, and which product was healthier, contained more calories, sugar, saturated fat, and sodium.</p> Results <p>Nutri-Score influenced purchasing intentions for four categories; warning labels only for one. Overall, Nutri-Score was somewhat more effective in guiding consumers to identify healthier choices and products higher in nutrients that should be consumed in moderation compared to the warning labels, although effects varied substantially between product categories and nutrients.</p> Conclusion <p>Both Nutri-Score and warning labels potentially promote healthier food choices, with Nutri-Score producing somewhat larger and more consistent effects. More research is needed on potential negative consequences of labels and the conditions under which they might appear to maximize public health benefit.</p>