GPT-6 Astra vs GPT-5.6 Sol
GPT-6 Astra (OpenAI) and GPT-5.6 Sol (OpenAI) compared on price, context window, speed and independent benchmarks. GPT-6 Astra scores higher on the Artificial Analysis Intelligence Index (61.2 vs 60.9), while GPT-5.6 Sol is 2.5× cheaper on a blended basis. Pick GPT-6 Astra for the hardest tasks and GPT-5.6 Sol when cost dominates.
| GPT-6 Astra | GPT-5.6 Sol | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Input $/1M | $10.0 | $4.00 |
| Output $/1M | $50.0 | $20.0 |
| Blended $/1M (3:1) | $20.0 | $8.00 |
| Cached input $/1M | $1.00 | $0.40 |
| Context window | 1.1M | 1.1M |
| Knowledge cutoff | 2026-04 | 2026-02 |
| License | proprietary | proprietary |
| Speed (tok/s) | — | 81 |
| Artificial Analysis Intelligence Index | 61.2 | 60.9 |
| LMArena Elo | — | 1455 |
| GPQA Diamond | 96.1% | 94.1% |
| Humanity's Last Exam | 54.7% | 49.5% |