AI Model Atlas / OpenAI
GPT-5.6 Luna
One million input tokens cost $0.20 and one million output tokens $1.20. Context window: 1.1M tokens, about 1,750 A4 pages.
What it costs in practice
Pricing per million tokens doesn't mean anything to anyone, so I convert it to three tasks that people actually give to models. The usage assumptions are listed for each row so you can verify them.
| Task | Input | Output | Cost |
|---|---|---|---|
| 1500-word articlebrief plus finished text in English | 1,500 tokens | 2,200 tokens | $0.0029 |
| 100 chat queries700 tokens per question and 400 per answer | 70,000 tokens | 40,000 tokens | $0.06 |
| Hour of work with an agentagent reads repository and writes fixes | 250,000 tokens | 30,000 tokens | $0.09 |
Technical details
| Provider | OpenAI |
| Modalities | files + image + text → text |
| Context window | 1.1M tokens (~1,750 A4 pages) |
| Maximum response | 128k tokens |
| Step-by-step reasoning | yes |
| Tool calling | yes |
| Forced JSON format | yes |
| Knowledge cutoff | 2026-02-16 |
| Cache read | $0.020 per million |
| Content moderation | yes, provider filters |
How it compares to the rest
The database contains 469 models. In terms of input pricing GPT-5.6 Luna is more expensive than 30 percent of paid models. A longer context window is available in 7 models.
Input price history
2026-09-08 · $0.202026-11-11 · $0.20
The chart shows the price of a million input tokens on consecutive measurement days. History starts on the day I launched the atlas and grows with each day. I don't backfill data.
Alternatives at a similar price
Models from other providers whose cost for the same article comes out closest.
| Model | Input / M | Output / M | 1500-word article | Context |
|---|---|---|---|---|
| DeepSeek V3 0324DeepSeek | $0.29 | $1.14 | $0.0029 | 164k |
| Gemini 3.5 Flash Lite (batch)Google | $0.15 | $1.25 | $0.0030 | 1M |
| Step 3.7 FlashStepfun | $0.20 | $1.15 | $0.0028 | 262k |
| Motif 3Motif technologies | $0.30 | $1.20 | $0.0031 | 262k |
Compare GPT-5.6 Luna with another model or go back to the full database 469 models.