LongCat 2.5 Preview vs GPT-5.6 Luna
GPT-5.6 Luna is cheaper on output tokens, while GPT-5.6 Luna offers a larger context window. Choose LongCat 2.5 Preview or GPT-5.6 Luna based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | LongCat 2.5 Preview | GPT-5.6 Luna |
|---|---|---|
| Provider | NanoGPT | OpenAI |
| Input / 1M tokens | $0.75 | $0.20 |
| Output / 1M tokens | $2.95 | $1.20 |
| Context window | 1M | 1.1M |
| Parameters | — | — |
| Open weights | No | — |
| Released | Sep 2026 | — |
| LMArena (Chatbot Arena) Elo score | — | 1431 |
| LMArena WebDev Elo score | — | 1518 |
| LMArena Vision Elo score | — | 1257 |
| GPQA Diamond score | — | 91.6 |
| Epoch Capabilities Index score | — | 157 |
FAQ
Is LongCat 2.5 Preview or GPT-5.6 Luna cheaper?
GPT-5.6 Luna is cheaper on output tokens ($1.20 vs $2.95 per 1M).
Which has the larger context window, LongCat 2.5 Preview or GPT-5.6 Luna?
GPT-5.6 Luna has the larger context window (1.1M tokens).
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.