For the same usage, Claude Sonnet 5.5 is 1.1× cheaper than GPT-5.6 Terra: at 1,000 requests a day of 2,000 input and 500 output tokens, that's $270.00 vs $300.00 a month.
| Item | Claude Sonnet 5.5 | GPT-5.6 Terra |
|---|---|---|
| Input | $2.00 | $2.00 |
| Cached input | $0.20 | $0.20 |
| Output | $10.00 | $12.00 |
| Context | 1,000,000 | 1,050,000 |
| Example per month | $270.00 | $300.00 |
Price isn't everything: test both models on your own tasks. If the cheaper one needs more retries, the gap shrinks.
It depends on the task. Bigger models make fewer mistakes on long reasoning and code; smaller ones answer faster and cost less. Measure with real cases.
For daily personal use, plans (Claude Pro, ChatGPT Plus) usually pay off. For products, automation and variable volume, the API. See the subscription vs API calculator.
Estimate based on public prices as of October 2026. Token counts vary with the text and the model; check the official pricing page before you decide.