Cogito v2.1, released by the Deep Cogito Team, is a 671 billion parameter Mixture of Experts model that claims to be the most competitive open-weight large language model (LLM) by a US company, excelling in industry benchmarks and internal evaluations. It is designed for enhanced reasoning capabilities, improved instruction following, coding, handling longer queries, multi-turn interactions, and creative tasks, while using fewer tokens compared to similar models. Users can access Cogito v2.1 via a free chat interface at chat.deepcogito.com, where no data is stored, or through various platforms like Huggingface, OpenRouter, Fireworks AI, Together AI, Ollama’s cloud, Baseten, and RunPod. The model is trained with process supervision to strengthen its reasoning process and is available for local deployment with specific hardware requirements, including a quantized version for more efficient serving. The release emphasizes real-world performance and encourages user testing to evaluate its capabilities in practice.