Kimi K2 vs UI-TARS-2

Moonshot AI

Kimi K2, released by Moonshot AI on July 11, 2025, is an open-weight Mixture-of-Experts large language model with 1 trillion total parameters and 32 billion active parameters per inference. It features a 256K token context window (expanded from 128K in an September 2025 update) and demonstrated strong performance on agentic coding benchmarks. Kimi K2 targets software engineering agents, tool-use workflows, and open-source deployments under a modified MIT license.

ByteDance

UI-TARS-2, released by ByteDance in September 2025, is a major generational upgrade of the UI-TARS family of GUI interaction models, with enhanced capabilities across computer control, game environments, code generation, and tool use. It targets agentic workflows requiring robust multimodal understanding of graphical interfaces across diverse application domains.