Claude Sonnet 5.5 vs GPT-6.1 Terra (Fast)
Both have similar output pricing, while GPT-6.1 Terra (Fast) offers a larger context window. Choose Claude Sonnet 5.5 or GPT-6.1 Terra (Fast) based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | Claude Sonnet 5.5 | GPT-6.1 Terra (Fast) |
|---|---|---|
| Provider | Anthropic | Vercel AI Gateway |
| Input / 1M tokens | $2.00 | $2.00 |
| Output / 1M tokens | $10.00 | $10.00 |
| Context window | 1M | 1.1M |
| Parameters | — | — |
| Open weights | — | No |
| Released | — | Oct 2026 |
| Epoch Capabilities Index score | 166 | — |
| LMArena (Chatbot Arena) Elo score | 1473 | — |
| GPQA Diamond score | 95.6 | — |
| LMArena WebDev Elo score | 1768 | — |
| LMArena Vision Elo score | 1287 | — |
FAQ
Is Claude Sonnet 5.5 or GPT-6.1 Terra (Fast) cheaper?
Claude Sonnet 5.5 and GPT-6.1 Terra (Fast) have comparable output pricing.
Which has the larger context window, Claude Sonnet 5.5 or GPT-6.1 Terra (Fast)?
GPT-6.1 Terra (Fast) has the larger context window (1.1M tokens).
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.