Summary Mango by‐products are considered cheap sources of valuable foods and nutraceutical ingredients. In this work, antioxidant capacity (AOX), and potential absorption ability (PAA) of extractable polyphenols (EP) from mango by‐product snacks (MB‐S) were evaluated at different stages of in vitro gastrointestinal digestion. A wheat and oat‐based control snack and three MB‐S formulations (F1, F2 and F3) were prepared. Mango by‐products were added at the expense of wheat in MB‐S (paste‐peel‐seed): F1 (70‐30‐0), F2 (70‐15‐15), F3 (70‐7.5‐22.5). The highest release of polyphenols was observed after the gastric digestion. In the intestinal stage, MB‐SF1 was the snack with the highest EP content (23.39 mg GAE/g db), two times greater than the control. Gallic acid and mangiferin were the main polyphenols identified in MB‐S. The incorporation of mango seed in the MB‐S reduced the polyphenols PAA by 10.29%. However, compared with the control snack, consumption of 30 g MB‐SF1 provided additional 45 mg polyphenols.