GPT-5.6 Luna API pricing — cost per million tokens
OpenAI's GPT-5.6 Luna costs $0.2 per million input tokens and $1.2 per million output tokens on the standard API tier (verified 2026-09-02). Note: Cut 80% from $1 / $6 on 2026-07-30; now matches GPT-5.4 nano on input. Compare it in the full pricing table or price your own prompts in the token cost calculator.
GPT-5.6 Luna price per million tokens
| direction | $ / Mtok | $ / 1K tokens |
|---|---|---|
| input (prompt) | $0.2 | $0.0002 |
| output (completion) | $1.2 | $0.0012 |
What real requests cost on GPT-5.6 Luna
| workload | input | output | total |
|---|---|---|---|
| Chat message (1K in / 500 out) | $0.0002 | $0.0006 | $0.0008 |
| Long document (100K in / 2K out) | $0.02 | $0.0024 | $0.0224 |
| Agent session (500K in / 50K out) | $0.10 | $0.06 | $0.16 |
How GPT-5.6 Luna pricing compares
GPT-5.6 Luna is currently the cheapest model we track — every other model costs more per request. Output tokens dominate long generations: at $1.2/Mtok, a 50K-token agent transcript costs $0.06 in output alone. Official rate card: OpenAI pricing.
Related: GPT-5.6 Sol pricing · GPT-5.6 Terra pricing · GPT-5.5 pricing · release timeline
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