Grok 4.20 is a reasoning model from SpaceXAI with industry-leading speed and agentic tool calling capabilities. It combines the lowest hallucination rate on the market with strict prompt adherance, delivering...
SpaceXAI: Grok 4.20 — xAI. Context window 2,000,000 tokens. API pricing (per 1M tokens): Input $1.25, Output $2.5. License: Proprietary. LMArena 1,451. GPQA Diamond 89.3%.
| Provider | xAI |
|---|---|
| API model ID | x-ai/grok-4.20 |
| Tier | Frontier |
| Context window | 2,000,000 tokens |
| Max output | 1,800,000 tokens |
| License | Proprietary |
| API pricing (per 1M tokens) · Input | $1.25 |
| API pricing (per 1M tokens) · Output | $2.5 |
| LMArena | 1,451 (grok-4.20-beta-0309-reasoning) |
| GPQA Diamond | 89.3% |
LMArena (CC-BY 4.0, best reasoning setting, 2026-10-02) · GPQA Diamond: Epoch AI (CC-BY 4.0)
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