OpenAI API pricing
List prices for 4 OpenAI models per million tokens, and what 1,000 requests a day cost.
4models
| Model | Input / 1M | Cached / 1M | Output / 1M | Per month | AA Intelligence Index |
|---|---|---|---|---|---|
| GPT 5.6 Luna | $0.200 | $0.020 | $1.20 | $30 | 37.3 |
| GPT 5.6 Terra | $2.00 | $0.200 | $12 | $300 | 42.1 |
| GPT 5.6 Sol | $4.00 | $0.400 | $20 | $540 | 47.0 |
| GPT 5.5 | $5.00 | $0.500 | $30 | $750 | 38.4 |
Per month: 1,000 requests a day, 2,000 input and 500 output tokens each, no caching, 30 days.
Data: real-api-pricing (MIT) · prices as of Oct 16, 2026
Questions
- What is the cheapest OpenAI API model?
- GPT 5.6 Luna has the lowest list price of the 4 OpenAI models here: $0.200 per 1M input tokens and $1.20 per 1M output tokens. At 1,000 requests a day (2,000 input and 500 output tokens each) that comes to about $30 a month.
- Which OpenAI model costs the most?
- GPT 5.5, at $5.00 per 1M input tokens and $30 per 1M output tokens: about $750 a month for the same workload.
- Is cached input cheaper on OpenAI?
- Yes. On GPT 5.6 Luna, cached input is $0.020 per 1M tokens against $0.200 for fresh input.