Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | Step 3.5 Flash 2603 | GPT-5.4 nano (xhigh) |
|---|---|---|
| Input ($/M tokens) | $0 | $0.2 |
| Output ($/M tokens) | $0 | $1.25 |
Data from Artificial Analysis API — 12 benchmarks
Step 3.5 Flash 2603 is cheaper overall. Its blended price (3:1 input/output ratio) is $0.00/M tokens vs $0.46/M for GPT-5.4 nano (xhigh).
GPT-5.4 nano (xhigh) wins 6 out of 12 benchmarks compared to 1 for Step 3.5 Flash 2603. See the detailed benchmark chart above for per-category results.
Step 3.5 Flash 2603 generates tokens faster at 161 tok/s vs 147 tok/s. Step 3.5 Flash 2603 also has lower time-to-first-token (0.80s vs 3.00s).
Choose based on your priorities: Step 3.5 Flash 2603 for lower cost, GPT-5.4 nano (xhigh) for stronger benchmark performance, and Step 3.5 Flash 2603 for faster generation. For latency-sensitive apps, check the TTFT comparison above.