GPT-5.6 Sol vs GPT-5.6 Luna Codex credit cost
On a daily-coding request, GPT-5.6 Sol costs about 1.4 Codex credits ($0.06) versus 0.1 credits ($0.00) for GPT-5.6 Luna, so GPT-5.6 Sol costs about 18.1x as much. Both meter at $0.04 per credit, i.e. exact OpenAI API rates. Verified 2026-08-22.
| GPT-5.6 Sol | GPT-5.6 Luna | |
|---|---|---|
| Input, credits / 1M | 100 | 5 |
| Output, credits / 1M | 500 | 30 |
| API rate in / out, $ / 1M | $4.00 / $20.00 | $0.20 / $1.20 |
| Daily-coding request | 1.4 cr ($0.06) | 0.1 cr ($0.00) |