Updated March 26, 2026· Based on independent benchmark data
Gemini 3.1 Pro Preview leads in intelligence with a score of 57.2 vs 13.8. For speed, Gemini 3.1 Pro Preview wins at 113 tok/s vs 0 tok/s.
| Metric | Gemini 1.5 Flash (Sep '24) | Gemini 3.1 Pro Preview |
|---|---|---|
| Intelligence Score | 13.8 | 57.2 |
| Coding Score | N/A | 55.5 |
| Math Score | N/A | N/A |
| Speed (tok/s) | 0 tok/s | 113 tok/s |
| Latency (TTFT) | 0.00s | 23.84s |
| Input Price / 1M tokens | Free | $2.00 |
| Output Price / 1M tokens | Free | $12 |
| Context Window | N/A | 1.0M |
| Max Output Tokens | N/A | N/A |
| Input Modalities | Text | Audio + File + Image + Text + Video |
Gemini 3.1 Pro Preview outperforms Gemini 1.5 Flash (Sep '24) on the intelligence index with a score of 57.2 compared to 13.8.
Gemini 3.1 Pro Preview generates output significantly faster at 113 tok/s compared to Gemini 1.5 Flash (Sep '24)'s 0 tok/s, making it Infinityx faster for streaming responses. Time to first token is 0.00s for Gemini 1.5 Flash (Sep '24) vs 23.84s for Gemini 3.1 Pro Preview, which affects perceived responsiveness in interactive applications.
Gemini 1.5 Flash (Sep '24) is completely free, while Gemini 3.1 Pro Preview costs $2.00/1M input tokens and $12/1M output tokens.
Choose Gemini 3.1 Pro Preview when you need higher intelligence (57.2), faster output (113 tok/s).
Gemini 3.1 Pro Preview is faster, producing output at 113 tok/s compared to Gemini 1.5 Flash (Sep '24)'s 0 tok/s.
No, Gemini 1.5 Flash (Sep '24) does not support image input. However, Gemini 3.1 Pro Preview does support images.
It depends on your priorities. Gemini 3.1 Pro Preview scores higher on intelligence (57.2), but Gemini 1.5 Flash (Sep '24) may be better for specific use cases like cost savings or speed-critical applications.
Data last synced: March 26, 2026
| Output Modalities | Text | Text |
| Free Tier | Yes | No |