license, SeamlessM4T embodies a commitment to open science. The alignment metadata of SeamlessAlign—comprising 270,000 hours of speech and text data—has been released to foster further independent research. Addressing previous challenges in the realm of multilingual communication, SeamlessM4T integrates speech-to-speech and speech-to-text tasks within a unified model, unlike its predecessors which were limited by separate systems and fewer languages. This innovation builds upon the success of projects such as No Language Left Behind and Universal Speech Translator, offering superior performance in both high-resource and lo