Sonar Reasoning Pro vs Step 3.5 Flash
Perplexity vs StepFun — benchmarks, pricing, and capabilities side by side.
- •Sonar Reasoning Pro has the higher intelligence index (95.7 vs 83.1)
- •Step 3.5 Flash is cheaper ($0.09 vs $2.00 per 1M input)
- •Step 3.5 Flash has a larger context window (262K)
| Sonar Reasoning Pro | Step 3.5 Flash | |
|---|---|---|
| Intelligence index | 95.7 | 83.1 |
| Developer | Perplexity | StepFun |
| Type | Multimodal | LLM |
| Access | API only | Open weights |
| Context window | 128,000 tokens | 262,144 tokens |
| Input price | $2.00 / 1M | $0.09 / 1M |
| Output price | $8.00 / 1M | $0.30 / 1M |
| Speed | — | 194 tok/s |
| Released | March 7, 2025 | January 29, 2026 |
| Parameters | — | — |
| Input modalities | Text, Image | Text |
| Output modalities | Text | Text |