A side-by-side comparison of Claude Opus 5.5 and GPT-6.1 Terra: input/output pricing, capabilities and available endpoints, served live from 370.AI. Both are reachable with the same API key.
| Item | Claude Opus 5.5 | GPT-6.1 Terra |
|---|---|---|
| Input (per 1M tokens) | $3.6 | $0.65 |
| Output (per 1M tokens) | $18 | $3.25 |
| Cache read explicit (per 1M tokens) | $0.18 | $0.0325 |
| Cache write 5m (per 1M tokens) | $4.5 | $0.8125 |
| Item | Claude Opus 5.5 | GPT-6.1 Terra |
|---|---|---|
| Context window | 1,000,000 | 922,000 |
| Max output | 128,000 | 128,000 |
| Item | Claude Opus 5.5 | GPT-6.1 Terra |
|---|---|---|
| function_calling | Yes | Yes |
| prompt_caching | Yes | Yes |
| vision | Yes | Yes |
On input, GPT-6.1 Terra is cheaper ($3.6 vs $0.65 per 1M tokens). On output, GPT-6.1 Terra is cheaper ($18 vs $3.25 per 1M tokens). All prices are per million tokens in USD.
Claude Opus 5.5 does — Claude Opus 5.5 accepts 1,000,000 input tokens and GPT-6.1 Terra accepts 922,000.
both support function_calling, prompt_caching, vision.
Yes. Both are available on 370.AI through one API key and the same OpenAI-compatible endpoint — switching means changing the model field from "claude-opus-5-5" to "gpt-6.1-terra", nothing else.
Both are available on 370.AI under one API key — switching between them means changing the model field and nothing else, so you can use each where it fits rather than picking one.