Gemini 2.5 Flash vs GPT-5.1-Codex
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 2.5 Flash vs GPT-5.1-Codex: side by side
| Spec | Gemini 2.5 Flash | GPT-5.1-Codex | Winner |
|---|---|---|---|
| Intelligence | 20.6 | 43.1 | GPT-5.1-Codex |
| Output speed | 208 t/s | 178 t/s | Gemini 2.5 Flash |
| Output price | $2.50/1M | $10.00/1M | Gemini 2.5 Flash |
| Context | 1049K | 400K | Gemini 2.5 Flash |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | OpenAI | Tie |
Gemini 2.5 Flash
Pros
- +Broad native support for multiple input modalities
- +Efficient handling of very large contexts
- +Strong balance of speed and capability
- +Versatile across text, vision and audio tasks
Cons
- –Lower peak performance than larger Gemini variants on complex tasks
- –Speed optimizations may reduce depth on nuanced reasoning
- –Practical limits on full 1M-token context utilization
GPT-5.1-Codex
Pros
- +Strong performance on extended coding workflows
- +Effective integration of visual context with code
- +Handles very large inputs without losing coherence
- +Specialized for software development tasks
Cons
- –Limited to text and image inputs only
- –High computational cost for maximum context
- –May require careful prompt engineering for complex tasks
Frequently asked questions
It depends on your needs. Gemini 2.5 Flash and GPT-5.1-Codex are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.