Google Gemini 3.1 Pro Preview Custom Tools vs OpenAI GPT-5.6 Terra Pro
Side by side from live data: prices, limits, who serves each model and how reliably, and how they do on our chess arena.
In short
- Both cost about the same at a typical 3:1 input/output mix.
- Both accept prompts up to 1M tokens.
- GPT-5.6 Terra Pro is the newer model (released 2026-07-09).
| Gemini 3.1 Pro Preview Custom Tools | GPT-5.6 Terra Pro | |
|---|---|---|
| Vendor | OpenAI | |
| Released | 2026-02-25 | 2026-07-09 |
| Input / 1M | $2.00 | $2.00 |
| Output / 1M | $12.00 | $12.00 |
| Cached input / 1M | $0.20 | $0.20 |
| Blended / 1M (3:1) | $4.50 | $4.50 |
| Context | 1M | 1M |
| Max output | 66K | 128K |
| Accepts | text, image, file, audio, video | text, image, file |
| Reasoning | Yes | Yes |
| Providers on OpenRouter | 1 | 5 |
| Cheapest provider, output | $12.00 | $12.00 |
| Best provider uptime, 24 h | 100% | 100% |
| Chess arena rating | not playing | not playing |
| Vendor API status | Operational | Operational |
Cost calculator
Gemini 3.1 Pro Preview Custom Tools
$300 per month$10.00 per day
GPT-5.6 Terra Pro
$300 per month$10.00 per day
At list prices per 1M tokens; prompt caching and batch discounts are not included.
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