Pyyan / Compare / Grok 4.20 Reasoning vs GPT-5.6 Sol
Grok 4.20 Reasoning vs GPT-5.6 Sol
2 of 5Language Models · verified 13 Aug 2026
Grok 4.20 ReasoningxAIcurrent
GPT-5.6 SolOpenAIcurrent| Specification | Grok 4.20 Reasoning | GPT-5.6 Sol |
|---|---|---|
| Summary | Agentic reasoning SKU. | Flagship tier of the GPT-5.6 family. |
| Context | 1M | 1M+ |
| Input ($/Mtok) | $1.25 | — |
| Output ($/Mtok) | $2.5 | — |
| Licence | Proprietary | Proprietary |
| Released | — | 9 Jul 2026 |
| Model ID | grok-4.20-0309-reasoning | — |
| Category | Language Models | Language Models |
| Official | xAI ↗ | OpenAI ↗ |
Highlighted rows are where these differ.
GPT-5.6 Sol
- Three tiers: Sol, Terra, Luna
- Adjustable reasoning effort from none to max
- Broad rollout began 9 July 2026
Best for all-round work.