DeepSeek V4.1 Flash 1017 as a Labs experiment, open for a short test window: temporary, not a permanent id. DeepSeek's October 17 update to V4.1 Flash, served from the official DeepSeek-V4.1-Flash-1017 open weights: the same 552B mixture-of-experts (8B active per token on prefill, 16B on decode) with native image understanding and a 1M-token context, on new weights that DeepSeek reports as stronger on reasoning, coding, agentic and visual benchmarks with shorter outputs. Reasoning has four modes: non-think (none), think low (low), think high (high, the default) and think max (max). Access is seat-gated through the Labs page while an experiment is live. It is offered at limited capacity and low availability, so expect it to be flaky and to go down under load: crash it, give it a moment, and try again. For production work we recommend the pay-per-token umans-deepseek-v4.1-flash.