Compare models
Pick up to 4. Every model here is free in free-pi.
| Attribute | Particle | GPT-6.1 Sol Flex | Solar Pro 4 | GPT-6 Luna |
|---|---|---|---|---|
| Maker | — | OpenAI | Upstage | OpenAI |
| Usage in free-pi | 🔥 Free Unlimited: limited time | slower · ~41x usage | ~0.6x usage | ~2.0x usage |
| Intelligence index | — | 54.6 (best) | 28.2 | 27.9 |
| Coding index | — | — | 52.7 | — |
| Context window | — | 1,050,000 tokens (best) | 524,288 tokens | 1,050,000 tokens (best) |
| Max output | — | 128,000 tokens | 131,072 tokens (best) | 128,000 tokens |
| Inputs | — | Text, image, file (best) | Text | Text, image, file (best) |
| Tool calling | — | Yes | Yes | Yes |
| Reasoning effort | — | Yes | Yes | Yes |
| Structured output | — | Yes | Yes | Yes |
| Released | — | Sep 29, 2026 | Aug 10, 2026 | Sep 22, 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.