Home / Compare / Gemini 3.1 Pro Preview vs GPT-5.6 Terra

Gemini 3.1 Pro Preview vs GPT-5.6 Terra

For a typical chat reply (2,000 tokens in, 400 out), GPT-5.6 Terra costs about the same as Gemini 3.1 Pro Preview: $8.80 against $8.80 per 1,000 requests at list price on 2026-09-28.

Gemini 3.1 Pro PreviewGPT-5.6 Terra
Input, per 1M tokens$2.00$2.00
Output, per 1M tokens$12.00$12.00
Context window1.05M1.05M
Classification or routing (600 tokens in, 10 out), per 1,000$1.32$1.32
Chat reply (2,000 in, 400 out), per 1,000$8.80$8.80
Retrieval-augmented answer (8,000 in, 500 out), per 1,000$22.00$22.00
Confidence signalnono
Tool callingyesyes

Which one should carry your traffic?

If Gemini 3.1 Pro Preview answers your requests as well as GPT-5.6 Terra, moving that traffic saves 0% on chat-shaped requests. Averages cannot tell you whether it does for your requests. Gemini 3.1 Pro Preview does not expose a confidence signal through OpenRouter, so Gimbix would test it as a full replacement rather than a first answer.

Gemini 3.1 Pro Preview profile · GPT-5.6 Terra profile · Measure it on your traffic