GPT-5.6 Sol vs Step 3.5 Flash
Side-by-side API pricing and Artificial Analysis performance for GPT-5.6 Sol (OpenAI) and Step 3.5 Flash (Stepfun). Green cells mark the better value in each row.
Prices updated Sep 19, 2026, 2:07 PM UTC · refreshed hourly
| GPT-5.6 Sol OpenAI | Step 3.5 Flash Stepfun | |
|---|---|---|
| Pricing | ||
| Input $/1M | $2.00 | $0.10 |
| Output $/1M | $10.00 | $0.30 |
| Blended $/1M (3:1) | $4.00 | $0.15 |
| RAG example (30K in / 2K out) | $0.08 | $0.0036 |
| Quality & speed | ||
| Intelligence Index | 47.1 | 17 |
| Coding Index | 77.4 | — |
| Agentic Index | 50.5 | — |
| Output speed (tok/s) | 65 | 0 |
| Time to first token | 71.18s | 0s |
| Specs | ||
| Context window | 1.05M | 262K |
| Input modalities | file, image, text | text |
FAQ
Which is cheaper, GPT-5.6 Sol or Step 3.5 Flash?
Step 3.5 Flash has the lower blended API price at $0.15 per 1M tokens (3:1 input:output mix), versus $4.00 for the other model. Prices are live from OpenRouter and refresh about hourly.
Which is better for RAG workloads?
For a typical RAG request (30K input / 2K output tokens), Step 3.5 Flash costs about $0.0036 per request versus $0.08. Also compare context windows: GPT-5.6 Sol offers 1.05M and Step 3.5 Flash offers 262K.
Which scores higher on Artificial Analysis benchmarks?
GPT-5.6 Sol leads on the Artificial Analysis Intelligence Index (47.1 vs 17). Check coding and agentic indices on this page for workload-specific tradeoffs.