GPT-5.1 vs GPT-5.5 Pro
GPT-5.1 is cheaper on output tokens, while GPT-5.5 Pro offers a larger context window. Choose GPT-5.1 or GPT-5.5 Pro based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | GPT-5.1 | GPT-5.5 Pro |
|---|---|---|
| Provider | OpenCode Zen | OpenCode Zen |
| Input / 1M tokens | $1.07 | $30.00 |
| Output / 1M tokens | $8.50 | $180.00 |
| Context window | 400K | 1.1M |
| Parameters | — | — |
| Open weights | No | No |
| Released | Nov 2025 | Apr 2026 |
FAQ
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.