Gemini 3.1 Pro Preview vs GPT-6.1 Terra Pro
API pricing, context, and independently measured performance, side by side. GPT-6.1 Terra Pro starts 50% cheaper on input than Gemini 3.1 Pro Preview at list prices.
Gemini 3.1 Pro Preview
Google · released Feb 19, 2026
Best input$2.00 / MTok
Best output$12.00 / MTok
Context1.05M
Providers7
Fastest measured2.5s° TTFT · 554 tok/s
VisionToolsReasoningStructured outputPrompt caching
GPT-6.1 Terra Pro
OpenAI · released Oct 26, 2026
Best input$1.00 / MTok
Best output$5.00 / MTok
Context1.05M
Providers4
Fastest measured—
VisionToolsReasoningStructured outputPrompt caching
Cheapest providers, measuredUSD / MTOK
| MODEL | PROVIDER | INPUT | OUTPUT | TTFT | TPS | SMOKE |
|---|---|---|---|---|---|---|
| Gemini 3.1 Pro Preview |  Google | $2.00 | $12.00 | 2.9s° | 182° tok/s | — |
| Gemini 3.1 Pro Preview |  Google AI Studio | $2.00 | $12.00 | 2.5s° | 554° tok/s | — |
| GPT-6.1 Terra Pro |  OpenAI | $1.00 | $5.00 | — | — | — |
| GPT-6.1 Terra Pro |  Azure | $1.20 | $6.00 | — | — | — |
TTFT/TPS: ModelIndex-measured medians (P50, trailing 21d) · chat10k profile (~10K in / 200 out) · ° = measured via OpenRouter routing (adds a hop) · SMOKE: of 5 programmatic capability probes passed · methodology v1.1 — full details on each model page