Lip sync (AI video)

Lip sync in AI video means the character's mouth movements correspond to the audio in the clip. Veo 3.1 generates lip-synced dialogue natively — you describe what the character should say, and the model produces both the audio and the matching mouth movement. Other models can produce silent video that's then lip-synced to separate audio in post (via tools like Hedra or D-ID), but Veo's native lip sync is significantly more convenient.