Gemini 3.1 Pro Listed in Preview With Length-Tiered Pricing

Google lists Gemini 3.1 Pro among its preview models rather than its stable line. Pricing is tiered by prompt length: $2 input and $12 output per million tokens for prompts up to 200k tokens, rising to $4 and $18 above that. Batch pricing halves both tiers. Gemini 3.6 Flash, which Google lists as stable, is priced at $1.50 input and $7.50 output.

Google's published pricing and model pages do not state a context window for either model, so none is quoted here.