DeepSeek-V4.1-Flash-1017

DeepSeek's October 17, 2026 checkpoint of V4.1-Flash: the same 552B-backbone causal encoder-decoder MoE (about 8B active in prefill, 16B in decode, native image input, 1M context) with further post-training, released as open weights under MIT. The deepseek-flash API alias, the web app and the legacy V4-Flash names now serve it at unchanged prices. DeepSeek reports gains over the September 10 checkpoint on every row it reran (HLE 42.6 vs 36.8, Terminal-Bench 4.0 42.3 vs 31.2, DeepSWE 77.0 vs 74.2, AutomationBench 60.5 vs 54.8) along with shorter outputs and runtimes. NOT FILED: Agents' Last Exam (35.4) is a pass rate, while the corpus column holds the score component; Chartography (83.0) is with tools, while the corpus column is without tools; ProgramBench, Apex Bench, BabyVision and ZeroBench have no corpus column; the text-only HLE figure (44.0) is a subset. GPQA, Codeforces, Terminal-Bench 2.1/3.0, CyberGym and SEC-Bench Pro were not rerun for this checkpoint.