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Claude Sonnet 5 vs GPT-5.6 Luna: price comparison
Claude Sonnet 5 lists at $2 / $10 and GPT-5.6 Luna at $1 / $6 per 1M input/output tokens. GPT-5.6 Luna is cheaper on both input and output tokens.
List prices
| Claude Sonnet 5 | GPT-5.6 Luna | |
|---|---|---|
| Maker | Anthropic | OpenAI |
| Input / 1M tokens | $2 | $1 |
| Output / 1M tokens | $10 | $6 |
| Through Somnus (at 2×) | $1 / $5 | $0.5 / $3 |
Cost per request
| Workload | Claude Sonnet 5 | GPT-5.6 Luna |
|---|---|---|
| Chat reply (1.5k in / 500 out) | $0.0080 | $0.0045 |
| Summary of a long document (20k in / 800 out) | $0.05 | $0.02 |
| Code generation (4k in / 3k out) | $0.04 | $0.02 |
Computed from list prices. Actual token counts vary by tokenizer and prompt.
Which should you pick?
GPT-5.6 Luna is cheaper on both input and output tokens.
Price is only one factor. Try both on a sample of your own prompts — with Somnus that's the same key and the same code, only the model name changes.
Questions
Can I use Claude Sonnet 5 and GPT-5.6 Luna with one API key?
Yes. Both are available through Somnus from the same key and balance.
Are these the official prices?
They are the list prices per 1M tokens that Somnus bills usage at. Your credit is worth at least 2× what you pay.
Try both on your own prompts
Switch between Claude Sonnet 5 and GPT-5.6 Luna by changing one string. New accounts get $5 free.
Get free creditRelated
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