Model comparison · updated 2026-07-28
Side-by-side pricing for1 million tokens
| GPT-5.5 Pro | GPT-5.6 Luna | Verdict | |
|---|---|---|---|
| Provider | OpenAI | OpenAI | -- |
| Context window | 400K | 1.05M | -- |
| Input / 1M tokens | $30 | $1 | GPT-5.6 Luna is 30x cheaper |
| Output / 1M tokens | $180 | $6 | GPT-5.6 Luna is 30x cheaper |
| Output:input ratio | 6x | 6x | -- |
| Tier | frontier | budget | -- |
GPT-5.5 Pro
333,333 tokens
GPT-5.6 Luna
10,000,000 tokens
GPT-5.6 Luna gives you 30x more input for the same budget.
GPT-5.5 Pro
55,556 tokens
GPT-5.6 Luna
1,666,667 tokens
GPT-5.6 Luna gives you 30x more output for the same budget.