Updated March 26, 2026· Based on independent benchmark data
Gemini 3.1 Pro Preview leads in intelligence with a score of 57.2 vs 37.8. Step 3.5 Flash is 20.0x cheaper at $0.10/1M tokens vs $2.00/1M. For speed, Gemini 3.1 Pro Preview wins at 113 tok/s vs 85 tok/s.
| Metric | Step 3.5 Flash | Gemini 3.1 Pro Preview |
|---|---|---|
| Intelligence Score | 37.8 | 57.2 |
| Coding Score | 31.6 | 55.5 |
| Math Score | N/A | N/A |
| Speed (tok/s) | 85 tok/s | 113 tok/s |
| Latency (TTFT) | 2.68s | 23.84s |
| Input Price / 1M tokens | $0.10 | $2.00 |
| Output Price / 1M tokens | $0.30 | $12 |
| Context Window | N/A |
Gemini 3.1 Pro Preview outperforms Step 3.5 Flash on the intelligence index with a score of 57.2 compared to 37.8. For coding tasks, Gemini 3.1 Pro Preview has the edge with a coding score of 55.5 vs 31.6.
Gemini 3.1 Pro Preview generates output significantly faster at 113 tok/s compared to Step 3.5 Flash's 85 tok/s, making it 1.3x faster for streaming responses. Time to first token is 2.68s for Step 3.5 Flash vs 23.84s for Gemini 3.1 Pro Preview, which affects perceived responsiveness in interactive applications.
Step 3.5 Flash is more affordable at $0.10/1M input tokens ($0.30/1M 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, Step 3.5 Flash would cost approximately $0.60/month vs $12.00/month for Gemini 3.1 Pro Preview in input costs alone.
Choose Step 3.5 Flash when you need lower cost. Choose Gemini 3.1 Pro Preview when you need higher intelligence (57.2), stronger coding performance (55.5), faster output (113 tok/s).
Gemini 3.1 Pro Preview scores higher on coding benchmarks (55.5 vs 31.6), making it the better choice for programming tasks.
Step 3.5 Flash is cheaper at $0.10/1M input tokens vs $2.00/1M for Gemini 3.1 Pro Preview.
Gemini 3.1 Pro Preview is faster, producing output at 113 tok/s compared to Step 3.5 Flash's 85 tok/s.
No, Step 3.5 Flash 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 Step 3.5 Flash may be better for specific use cases like budget-conscious projects or speed-critical applications.