DeepSeek V4.1 Flash
DeepSeek V4.1 Flash: 552B MoE, 8B/16B active, KV cache 400x smaller than V1, MIT
DeepSeek's V4.1 Flash is a 552B-parameter multimodal MoE that activates only 8B parameters on prefill and 16B on decode, with a 1M-token context window, trained from scratch on 45 trillion multimodal tokens and released under MIT. It returns to an encoder-decoder architecture at half-trillion scale and cuts the KV cache to about 890 bytes per token, down from 389,000 bytes in the first DeepSeek release (over 400x smaller), which is why it is so cheap to serve. DeepSeek's own evals put it at 90.6 on Terminal-Bench 2.1 and 74.2 on DeepSWE 1.1, above Opus 5 and GPT-5.6 Sol, and second behind GPT-6 Astra on an Open Design leaderboard at about two cents per task. TokenJuice.ai serves it free in the US for a limited time in exchange for training data.