Grok-4-Fast-Reasoning vs GPT-5.5-Pro
Grok-4-Fast-Reasoning is cheaper on output tokens, while Grok-4-Fast-Reasoning offers a larger context window. Choose Grok-4-Fast-Reasoning or GPT-5.5-Pro based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | Grok-4-Fast-Reasoning | GPT-5.5-Pro |
|---|---|---|
| Provider | Poe | Poe |
| Input / 1M tokens | $0.20 | $27.27 |
| Output / 1M tokens | $0.50 | $163.64 |
| Context window | 2M | 400K |
| Parameters | — | — |
| Open weights | No | No |
| Released | Sep 2025 | Apr 2026 |
FAQ
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.