The closest alternative to DeepSeek V4 Flash 0731 is Gemini 3.6 Flash — comparable intelligence (50.1 vs 49.9); for a cheaper option, GPT-5.6 Luna runs $0.100/M vs $0.140/M; and the best open-weight substitute is Kimi K3.
Gemini 3.6 Flash is the closest alternative to DeepSeek V4 Flash 0731, with an Intelligence Index of 50.1 (DeepSeek V4 Flash 0731 scores 49.9) at $1.50 per million input tokens.
Yes — GPT-5.6 Luna costs $0.100 per million input tokens versus $0.140 for DeepSeek V4 Flash 0731, while staying within ~8 points of its Intelligence Index.
Kimi K3 is the strongest open-weight alternative to DeepSeek V4 Flash 0731 — downloadable from Hugging Face and self-hostable, scoring 57.1 on intelligence.