GPT-5.6 Luna vs Mistral Small 4
Price and specs side by side · USD per 1M tokens · verified 2026-10-11
// side by side
| metric | GPT-5.6 Luna | Mistral Small 4 |
|---|
| input / 1M | $0.20 | $0.15 |
| output / 1M | $1.20 | $0.60 |
| blended (3:1) | $0.45 | $0.2625 |
| cache read / 1M | $0.02 | $0.015 |
| context | 1.05M | 262.1K |
| max output | 128K | 256K |
| input types | text · image · pdf | text · image |
| reasoning | yes | yes |
| tool calling | yes | yes |
| structured output | yes | no |
| open weights | no | yes |
| released | 2026-07-09 | 2026-03-16 |
| knowledge cutoff | 2026-02-16 | 2025-06 |
| lab | OpenAI | Mistral |
// monthly cost scenarios
| workload | tokens in / out | GPT-5.6 Luna | Mistral Small 4 |
|---|
| Chatbot | 10M / 2M | $4.40 | $2.70 |
| RAG app | 50M / 5M | $16.00 | $10.50 |
| Coding agent | 20M / 10M | $16.00 | $9.00 |
// verdict
- Mistral Small 4 is 41.7% cheaper than GPT-5.6 Luna on a blended 3:1 input/output basis.
- GPT-5.6 Luna has the larger context window (1.05M vs 262.1K tokens).
- Only GPT-5.6 Luna supports structured output.