Updated March 26, 2026· Based on independent benchmark data
Gemini 3.1 Pro Preview leads in intelligence with a score of 57.2 vs 17.6. Gemini 2.5 Flash-Lite (Reasoning) is 20.0x cheaper at $0.10/1M tokens vs $2.00/1M. For speed, Gemini 2.5 Flash-Lite (Reasoning) wins at 329 tok/s vs 113 tok/s.
| Metric | Gemini 2.5 Flash-Lite (Reasoning) | Gemini 3.1 Pro Preview |
|---|---|---|
| Intelligence Score | 17.6 | 57.2 |
| Coding Score | 9.5 | 55.5 |
| Math Score | 53.3 | N/A |
| Speed (tok/s) | 329 tok/s | 113 tok/s |
| Latency (TTFT) | 11.34s | 23.84s |
| Input Price / 1M tokens | $0.10 | $2.00 |
| Output Price / 1M tokens | $0.40 | $12 |
| Context Window | N/A |
Gemini 3.1 Pro Preview outperforms Gemini 2.5 Flash-Lite (Reasoning) on the intelligence index with a score of 57.2 compared to 17.6. For coding tasks, Gemini 3.1 Pro Preview has the edge with a coding score of 55.5 vs 9.5.
Gemini 2.5 Flash-Lite (Reasoning) generates output significantly faster at 329 tok/s compared to Gemini 3.1 Pro Preview's 113 tok/s, making it 2.9x faster for streaming responses. Time to first token is 11.34s for Gemini 2.5 Flash-Lite (Reasoning) vs 23.84s for Gemini 3.1 Pro Preview, which affects perceived responsiveness in interactive applications.
Gemini 2.5 Flash-Lite (Reasoning) is more affordable at $0.10/1M input tokens ($0.40/1M output), while Gemini 3.1 Pro Preview costs $2.00/1M input ($12/1M output). That makes Gemini 3.1 Pro Preview 20.0x more expensive per token, which can add up significantly at scale. For a typical workload of 100 requests per day at 2,000 tokens each, Gemini 2.5 Flash-Lite (Reasoning) would cost approximately $0.60/month vs $12.00/month for Gemini 3.1 Pro Preview in input costs alone.
Choose Gemini 2.5 Flash-Lite (Reasoning) when you need faster output (329 tok/s), lower cost. Choose Gemini 3.1 Pro Preview when you need higher intelligence (57.2), stronger coding performance (55.5).
Gemini 3.1 Pro Preview scores higher on coding benchmarks (55.5 vs 9.5), making it the better choice for programming tasks.
Gemini 2.5 Flash-Lite (Reasoning) is cheaper at $0.10/1M input tokens vs $2.00/1M for Gemini 3.1 Pro Preview.
Gemini 2.5 Flash-Lite (Reasoning) is faster, producing output at 329 tok/s compared to Gemini 3.1 Pro Preview's 113 tok/s.
No, Gemini 2.5 Flash-Lite (Reasoning) does not support image input. However, Gemini 3.1 Pro Preview does support images.
Data last synced: March 26, 2026
| 1.0M |
| Max Output Tokens | N/A | N/A |
| Input Modalities | Text | Audio + File + Image + Text + Video |
| Output Modalities | Text | Text |
| Free Tier | No | No |
It depends on your priorities. Gemini 3.1 Pro Preview scores higher on intelligence (57.2), but Gemini 2.5 Flash-Lite (Reasoning) may be better for specific use cases like budget-conscious projects or speed-critical applications.