Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | Step 3.5 Flash 2603 | gpt-oss-20B (high) |
|---|---|---|
| Input ($/M tokens) | $0 | $0.05 |
| Output ($/M tokens) | $0 | $0.2 |
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 $0.09/M for gpt-oss-20B (high).
Step 3.5 Flash 2603 wins 7 out of 12 benchmarks compared to 4 for gpt-oss-20B (high). See the detailed benchmark chart above for per-category results.
gpt-oss-20B (high) generates tokens faster at 260 tok/s vs 158 tok/s. However, gpt-oss-20B (high) has lower time-to-first-token (0.40s vs 0.81s).
Choose based on your priorities: Step 3.5 Flash 2603 for lower cost, Step 3.5 Flash 2603 for stronger benchmark performance, and gpt-oss-20B (high) for faster generation. For latency-sensitive apps, check the TTFT comparison above.