Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | DeepSeek V4 Flash (Reasoning, Max Effort) | Step 3.5 Flash 2603 |
|---|---|---|
| Input ($/M tokens) | $0.14 | $0.1 |
| Output ($/M tokens) | $0.28 | $0.3 |
Data from Artificial Analysis API — 12 benchmarks
Step 3.5 Flash 2603 is cheaper overall. Its blended price (3:1 input/output ratio) is $0.15/M tokens vs $0.17/M for DeepSeek V4 Flash (Reasoning, Max Effort).
DeepSeek V4 Flash (Reasoning, Max Effort) wins 7 out of 12 benchmarks compared to 0 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 181 tok/s vs 100 tok/s. DeepSeek V4 Flash (Reasoning, Max Effort) also has lower time-to-first-token (1.01s vs 1.86s).
Choose based on your priorities: Step 3.5 Flash 2603 for lower cost, DeepSeek V4 Flash (Reasoning, Max Effort) for stronger benchmark performance, and Step 3.5 Flash 2603 for faster generation. For latency-sensitive apps, check the TTFT comparison above.