Kimi vs. OPT

Kimi

Kimi is Moonshot AI's open-weight family for long-context reasoning, coding, multimodal agents, and research. Kimi K3 is the current generation.

Moonshot AI launched Kimi in 2023 with an early focus on long-context document understanding. Kimi K3, released in July 2026, is a 2.8T-parameter mixture-of-experts model with 104B active parameters. It combines native vision, a one-million-token context window, long-horizon coding, knowledge work, reasoning, and agent orchestration. The full model weights are available under the Kimi K3 License.

Further reading

• github.com/MoonshotAI/Kimi-K2
• github.com/MoonshotAI/Kimi-K3
• huggingface.co/moonshotai/Kimi-K3

OPT

Open Pre-trained Transformer Language Models (OPT) is part of the family of open source models designed to replicate GPT-3, with similar decoder-only architecture. It has since been superseded by models such as LLaMA, GPT-J, and Pythia.