| GPT-5.4 Nano | GPT-5.6 Luna | |
|---|---|---|
| Input, per 1M tokens | $0.20 | $0.20 |
| Output, per 1M tokens | $1.25 | $1.20 |
| Context window | 400K | 1.05M |
| Classification or routing (600 tokens in, 10 out), per 1,000 | $0.133 | $0.132 |
| Chat reply (2,000 in, 400 out), per 1,000 | $0.90 | $0.88 |
| Retrieval-augmented answer (8,000 in, 500 out), per 1,000 | $2.23 | $2.20 |
| Confidence signal | no | no |
| Tool calling | yes | yes |
Which one should carry your traffic?
If GPT-5.6 Luna answers your requests as well as GPT-5.4 Nano, moving that traffic saves 2% on chat-shaped requests. Averages cannot tell you whether it does for your requests. GPT-5.6 Luna does not expose a confidence signal through OpenRouter, so Gimbix would test it as a full replacement rather than a first answer.
GPT-5.4 Nano profile · GPT-5.6 Luna profile · Measure it on your traffic