GPT-6.1 Terra vs Claude Sonnet 5.5
How OpenAI's GPT-6.1 Terra and Anthropic's Claude Sonnet 5.5 differ on paper, from the specs each provider publishes.
Compare them on your promptBoth answer side by side, free with your own API keys.
Key differences
- GPT-6.1 Terra accepts a larger context window: 1.05M tokens versus 1M for Claude Sonnet 5.5.
- GPT-6.1 Terra is the newer release (October 2026); Claude Sonnet 5.5 came out in September 2026.
Side by side
| Spec | GPT-6.1 Terra | Claude Sonnet 5.5 |
|---|---|---|
| Provider | OpenAI | Anthropic |
| Released | October 2026 | September 2026 |
| Context window | 1.05M tokens | 1M tokens |
| Max output | 128K tokens | 128K tokens |
| Reasoning model | Yes | Yes |
| Price per 1M tokens (in / out) | See provider | $2 / $10 |
| Capabilities | Image input, Reasoning, Coding, Tool calling, Structured output, Extended thinking, Streaming | Image input, Reasoning, Coding, Tool calling, Structured output, Extended thinking, Streaming |
Specs as published by each provider. Benchmarks and output quality aren't covered here; the best test is your own prompts.
Specs only go so far. Ask both.
Send one message and get GPT-6.1 Terra and Claude Sonnet 5.5's answers side by side, with response time, tokens and cost for each. You'll need OpenAI and Anthropic keys.
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