The closest alternative to Gemini 3.1 Flash Lite Preview is DeepSeek V3.2 — comparable intelligence (24.7 vs 25.0); for a cheaper option, GPT-5.6 Luna runs $0.100/M vs $0.250/M; and the best open-weight substitute is Kimi K3.
DeepSeek V3.2 is the closest alternative to Gemini 3.1 Flash Lite Preview, with an Intelligence Index of 24.7 (Gemini 3.1 Flash Lite Preview scores 25.0) at $0.269 per million input tokens.
Yes — GPT-5.6 Luna costs $0.100 per million input tokens versus $0.250 for Gemini 3.1 Flash Lite Preview, while staying within ~8 points of its Intelligence Index.
Kimi K3 is the strongest open-weight alternative to Gemini 3.1 Flash Lite Preview — downloadable from Hugging Face and self-hostable, scoring 57.1 on intelligence.