GPT-5.6 Terra vs Claude Sonnet 5
The mid-tier option from each provider, where most production work lands.
Side by side
| Attribute | GPT-5.6 Terra | Claude Sonnet 5 |
|---|---|---|
| Input, per 1M tokens | $2.00 | $2.00 |
| Output, per 1M tokens | $12.00 | $10.00 |
| Context window | 1,050,000 | 1,000,000 |
| Provider | OpenAI | Anthropic |
| Tokenizer | o200k_base | Anthropic tokenizer |
| Long-context tier | above 272,000 | none |
| Retires | no date announced | no date announced |
Which to choose
- Reading more than you write
- Both $2 per million input. Input rate cannot separate this pair.
- Writing more than you read
- GPT-5.6 Terra prices output at 6x its input rate, Claude Sonnet 5 at 5x — so Claude Sonnet 5's lead narrows as answers lengthen.
- Whole documents in one request
- Claude Sonnet 5 stops at 1,000,000; GPT-5.6 Terra takes 1,050,000. Past the lower ceiling only GPT-5.6 Terra accepts the request, at any price.
- Past the long-context threshold
- The ranking inverts (GPT-5.6 Terra above 272,000): GPT-5.6 Terra wins below the line, Claude Sonnet 5 above it at $2 against $4. Judging this pair on headline rates alone gives the wrong answer for large prompts.
- 10,000 in, 1,000 out
- $0.0320 on GPT-5.6 Terra, $0.0300 on Claude Sonnet 5. Over 10,000 such calls that is $20.00 in Claude Sonnet 5's favour.
- How these counts were arrived at
- GPT-5.6 Terra is counted exactly in your browser; Claude Sonnet 5 is estimated from a characters-per-token ratio. Close, not exact.
What this page does not tell you. Which model produces better answers. That depends on your task, and this site has no benchmark data — everything above is drawn from published pricing and specifications. Compare quality by running your own prompts through both.