Moonshot AI releases 2.8-trillion-parameter open model Kimi K3

Moonshot AI released Kimi K3, an open-weight mixture-of-experts (MoE) model with 2.8 trillion total parameters that activates only 16 of 896 experts per token. It introduces a new Kimi Delta Attention mechanism and supports a 1 million token context window. Full model weights are scheduled for release by July 27, 2026.

Why it matters: This is one of the largest open-weight models released to date, and per early third-party benchmarks it reportedly approaches GPT-5.6 Sol and Claude Fable 5 while beating Opus 4.8 and GLM 5.2 on some tasks — a notable jump for a Chinese lab. It's also reportedly significantly pricier to run than its predecessor, suggesting the era of ultra-cheap Chinese open models may be giving way to costlier, higher-capability ones.