Home / Compare / Gemini 3.1 Pro Preview vs Gemma 4 31B

Gemini 3.1 Pro Preview vs Gemma 4 31B

For a typical chat reply (2,000 tokens in, 400 out), Gemini 3.1 Pro Preview costs 28× as much as Gemma 4 31B: $8.80 against $0.316 per 1,000 requests at list price on 2026-09-28.

Gemini 3.1 Pro PreviewGemma 4 31B
Input, per 1M tokens$2.00$0.09
Output, per 1M tokens$12.00$0.34
Context window1.05M262K
Classification or routing (600 tokens in, 10 out), per 1,000$1.32$0.0574
Chat reply (2,000 in, 400 out), per 1,000$8.80$0.316
Retrieval-augmented answer (8,000 in, 500 out), per 1,000$22.00$0.89
Confidence signalnoyes
Tool callingyesyes
BANKING77, correct of 400not measured304

Which one should carry your traffic?

If Gemma 4 31B answers your requests as well as Gemini 3.1 Pro Preview, moving that traffic saves 96% on chat-shaped requests. Averages cannot tell you whether it does for your requests. Gemma 4 31B exposes a confidence signal, so Gimbix can let it answer first and hand unsure cases to Gemini 3.1 Pro Preview.

Gemini 3.1 Pro Preview profile · Gemma 4 31B profile · Measure it on your traffic