DeepSeek V4 launches with frontier-competitive models at a fraction of the cost

Chinese AI lab DeepSeek has released two preview models, DeepSeek-V4-Pro and DeepSeek-V4-Flash, both using a Mixture of Experts architecture with 1 million token context windows. V4-Pro, at 1.6T total parameters (49B active), is described as likely the largest open-weights model currently available — larger than Kimi K2.6 and GLM-5.1. The standout story is pricing: V4-Flash costs just $0.14/M input tokens, undercutting even GPT-5.4 Nano, while V4-Pro at $1.74/M input is the cheapest among larger frontier models. DeepSeek's paper attributes the low cost to dramatic efficiency gains, with V4-Pro using only 27% of the single-token FLOPs and 10% of the KV cache size of DeepSeek-V3.2 in a 1M-token context scenario.