Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | Gemini 2.5 Flash Preview (Sep '25) (Reasoning) | GPT-5.4 mini (Non-Reasoning) |
|---|---|---|
| Input ($/M tokens) | $0 | $0.75 |
| Output ($/M tokens) | $0 | $4.5 |
Data from Artificial Analysis API — 12 benchmarks
Gemini 2.5 Flash Preview (Sep '25) (Reasoning) is cheaper overall. Its blended price (3:1 input/output ratio) is $0.00/M tokens vs $1.69/M for GPT-5.4 mini (Non-Reasoning).
Gemini 2.5 Flash Preview (Sep '25) (Reasoning) wins 9 out of 12 benchmarks compared to 2 for GPT-5.4 mini (Non-Reasoning). See the detailed benchmark chart above for per-category results.
GPT-5.4 mini (Non-Reasoning) generates tokens faster at 202 tok/s vs 0 tok/s. Gemini 2.5 Flash Preview (Sep '25) (Reasoning) also has lower time-to-first-token (0.00s vs 0.45s).
Choose based on your priorities: Gemini 2.5 Flash Preview (Sep '25) (Reasoning) for lower cost, Gemini 2.5 Flash Preview (Sep '25) (Reasoning) for stronger benchmark performance, and GPT-5.4 mini (Non-Reasoning) for faster generation. For latency-sensitive apps, check the TTFT comparison above.