Google Gemini 3.1 Pro Preview Custom Tools vs OpenAI GPT-5.3-Codex
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.
- Gemini 3.1 Pro Preview Custom Tools accepts longer prompts: 1M vs 400K tokens.
| Gemini 3.1 Pro Preview Custom Tools | GPT-5.3-Codex | |
|---|---|---|
| Vendor | OpenAI | |
| Released | 2026-02-25 | 2026-02-24 |
| Input / 1M | $2.00 | $1.75 |
| Output / 1M | $12.00 | $14.00 |
| Cached input / 1M | $0.20 | $0.175 |
| Blended / 1M (3:1) | $4.50 | $4.81 |
| Context | 1M | 400K |
| Max output | 66K | 128K |
| Accepts | text, image, file, audio, video | text, image, file |
| Reasoning | Yes | Yes |
| Providers on OpenRouter | 1 | 3 |
| Cheapest provider, output | $12.00 | $14.00 |
| 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-5.3-Codex
$315 per month$10.50 per day
Gemini 3.1 Pro Preview Custom Tools saves $15.00 a month on this workload.
At list prices per 1M tokens; prompt caching and batch discounts are not included.
Compare Gemini 3.1 Pro Preview Custom Tools with