Kling 2.1 (Kling AI 2.1) – Kuaishou’s DiT video model, released May 29, 2025. Tiers: Std 720p, Pro 1080p, Master 1080p. Key upgrades: first/last frame control (+235%), better physics/motion, stable human/hand details, accurate text; faster, cost-effective—ideal for realism/Eastern aesthetics/commercial ads。