Compare models
Pick up to 4. Every model here is free in free-pi.
| Attribute | GPT-6 Luna | GPT-6.1 Sol Flex | Kimi K3.1 Pro | Particle |
|---|---|---|---|---|
| Maker | OpenAI | OpenAI | MoonshotAI | — |
| Usage in free-pi | ~2.0x usage | slower · ~41x usage | daily limit · ~41x usage | 🔥 Free Unlimited: limited time |
| Intelligence index | 27.9 | 54.6 (best) | 46.5 | — |
| Coding index | — | — | — | — |
| Context window | 1,050,000 tokens (best) | 1,050,000 tokens (best) | 1,048,576 tokens | — |
| Max output | 128,000 tokens | 128,000 tokens | 943,718 tokens (best) | — |
| Inputs | Text, image, file (best) | Text, image, file (best) | Text, image, video (best) | — |
| Tool calling | Yes | Yes | Yes | — |
| Reasoning effort | Yes | Yes | Yes | — |
| Structured output | Yes | Yes | Yes | — |
| Released | Sep 22, 2026 | Sep 29, 2026 | Oct 23, 2026 | — |
| Model page | Model page | Model page | Model page | Model page |
Stats refreshed automatically. Usage rate from free-pi. Green marks the best value in each row. “—” means no figure is available.