Gemini 2.5 Flash Lite Preview 09-2025 vs Gemini 3.1 Pro Preview Custom Tools
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 Lite Preview 09-2025 vs Gemini 3.1 Pro Preview Custom Tools: side by side
| Spec | Gemini 2.5 Flash Lite Preview 09-2025 | Gemini 3.1 Pro Preview Custom Tools | Winner |
|---|---|---|---|
| Intelligence | 19.4 | — | Tie |
| Output speed | — | — | Tie |
| Output price | $0.40/1M | $12.00/1M | Gemini 2.5 Flash Lite Preview 09-2025 |
| Context | 1049K | 1049K | Tie |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | Tie |
Gemini 2.5 Flash Lite Preview 09-2025
Pros
- +Optimized for speed and low latency
- +Handles very large context windows
- +Broad native multimodal support
- +Lightweight deployment suitable for high-volume use
Cons
- –Preview model may show inconsistent behavior
- –Reduced capability depth versus full Gemini variants
- –Lite design trades off some advanced reasoning performance
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
Frequently asked questions
It depends on your needs. Gemini 2.5 Flash Lite Preview 09-2025 and Gemini 3.1 Pro Preview Custom Tools are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.