Compare models
Pick up to 4. Every model here is free in free-pi.
| Attribute | GPT-6.1 Sol Flex | Particle | Solar Pro 4 | GPT-6.1 Terra |
|---|---|---|---|---|
| Maker | OpenAI | — | Upstage | OpenAI |
| Usage in free-pi | slower · ~41x usage | 🔥 Free Unlimited: limited time | ~0.6x usage | premium, uses allowance fast · ~20x usage |
| Intelligence index | 54.6 (best) | — | 28.2 | 51.3 |
| 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 | Oct 26, 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.