Claude Opus 5.5 vs GPT-6.1 Terra
In Endless, GPT-6.1 Terra costs less: 81 credits per 1M input tokens and 405 per 1M output tokens, against 324 credits per 1M input tokens and 1620 per 1M output tokens for Claude Opus 5.5. Claude Opus 5.5 is made by Anthropic, and GPT-6.1 Terra by OpenAI. Claude Opus 5.5 is available on the Hobby plan and up, and GPT-6.1 Terra on every plan.
| Detail | Claude Opus 5.5 | GPT-6.1 Terra |
|---|---|---|
| Maker | Anthropic | OpenAI |
| Type | Chat model | Chat model |
| Price | 324 credits per 1M input tokens · 1620 credits per 1M output tokens | 81 credits per 1M input tokens · 405 credits per 1M output tokens |
| Availability | Available on Hobby and above | Available on every plan |
| Context window | 1M tokens | Not listed |
| Max output | 128K tokens | Not listed |
| Inputs | Text, images | Not listed |
| Outputs | Text | Not listed |
| Added to Endless | Sep 22, 2026 | Oct 26, 2026 |
When to pick Claude Opus 5.5
- Codebase-wide migrations, refactors and audits
- Research reports with source-checked figures and quotes
- Excel models and presentations ready for executives
- Long agent runs that delegate work to subagents
When to pick GPT-6.1 Terra
- GPT-6.1 Terra is a chat model from OpenAI. Run the same prompt on both and keep the result you prefer.
Questions about Claude Opus 5.5 and GPT-6.1 Terra
- Which is cheaper in Endless, Claude Opus 5.5 or GPT-6.1 Terra?
- In Endless, GPT-6.1 Terra costs less: 81 credits per 1M input tokens and 405 per 1M output tokens, against 324 credits per 1M input tokens and 1620 per 1M output tokens for Claude Opus 5.5.
- Who makes Claude Opus 5.5 and GPT-6.1 Terra?
- Claude Opus 5.5 is made by Anthropic, and GPT-6.1 Terra by OpenAI.
- Which plan do I need for Claude Opus 5.5 and GPT-6.1 Terra?
- Claude Opus 5.5 is available on the Hobby plan and up, and GPT-6.1 Terra on every plan.
- Can I use Claude Opus 5.5 and GPT-6.1 Terra in the same workspace?
- Yes. Both are in Endless, so you can switch between them in chat and pay for both from one shared credit balance.
Use both in Endless
Claude Opus 5.5 and GPT-6.1 Terra sit in the same workspace. Pick either one in chat, ask both the same question and compare the answers. Your team pays for both from one shared credit balance.