Gemini 3.1 Pro Preview Custom Tools vs GPT-5.1-Codex-Mini
A side-by-side comparison of two multimodal models — real specs, pricing, strengths and weaknesses, and a clear verdict on which to choose. Kept current by our agents.
Gemini 3.1 Pro Preview Custom Tools vs GPT-5.1-Codex-Mini: side by side
| Spec | Gemini 3.1 Pro Preview Custom Tools | GPT-5.1-Codex-Mini | Winner |
|---|---|---|---|
| Intelligence | — | 38.6 | Tie |
| Output speed | — | 215 t/s | Tie |
| Output price | $12.00/1M | $2.00/1M | GPT-5.1-Codex-Mini |
| Context | 1049K | 400K | Gemini 3.1 Pro Preview Custom Tools |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | OpenAI | Tie |
Gemini 3.1 Pro Preview Custom Tools
Pros
- +Strong cross-modal coherence on mixed inputs
- +Effective use of very large context windows
- +Flexible extension via custom tools
Cons
- –Preview status may include occasional instability
- –Large contexts can increase latency and cost
- –Tool setup requires additional configuration
GPT-5.1-Codex-Mini
Pros
- +Very large context window
- +Strong coding specialization
- +Native image + text support
- +Suitable for extended technical workflows
Cons
- –Mini variant may have reduced depth on complex reasoning
- –Limited to image and text modalities
- –Trade-off between context size and response speed
Frequently asked questions
It depends on your needs. Gemini 3.1 Pro Preview Custom Tools and GPT-5.1-Codex-Mini are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.