DeepSeek-V4: Towards Highly Efficient Million-Token Context Intelligence DeepSeek AI released preview versions of its DeepSeek-V4 series, including two Mixture-of-Experts language models with up to 1.6 trillion parameters and support for one-million-token contexts. The models feature architectural innovations like hybrid attention and a new optimizer, achieving state-of-the-art performance while significantly reducing inference costs for long-context tasks. arXiv:2606.19348v1 Announce Type: new Abstract: We present a preview version of DeepSeek-V4 series, including two strong Mixture-of-Experts MoE language models -- DeepSeek-V4-Pro with 1.6T parameters 49B activated and DeepSeek-V4-Flash with 284B parameters 13B activated -- both supporting a context length of one million tokens. DeepSeek-V4 series incorporate several key upgrades in architecture and optimization: 1 a hybrid attention architecture that combines Compressed Sparse Attention CSA and Heavily Compressed Attention HCA to improve long-context efficiency; 2 Manifold-Constrained Hyper-Connections mHC that enhance conventional residual connections; 3 and the Muon optimizer for faster convergence and greater training stability. We pre-train both models on more than 32T diverse and high-quality tokens, followed by a comprehensive post-training pipeline that unlocks and further enhances their capabilities. DeepSeek-V4-Pro-Max, the maximum reasoning effort mode of DeepSeek-V4-Pro, redefines the state-of-the-art for open models, outperforming its predecessors in core tasks. Meanwhile, DeepSeek-V4 series are highly efficient in long-context scenarios. In the one-million-token context setting, DeepSeek-V4-Pro requires only 27% of single-token inference FLOPs and 10% of KV cache compared with DeepSeek-V3.2. This enables us to routinely support one-million-token contexts, thereby making long-horizon tasks and further test-time scaling more feasible. The model checkpoints are available at https://huggingface.co/collections/deepseek-ai/deepseek-v4.