grok-4.20-beta-0309-reasoning vs Grok 4.2 Fast Non Reasoning
Both have similar output pricing. Choose grok-4.20-beta-0309-reasoning or Grok 4.2 Fast Non Reasoning based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | grok-4.20-beta-0309-reasoning | Grok 4.2 Fast Non Reasoning |
|---|---|---|
| Provider | 302.AI | ZenMux |
| Input / 1M tokens | $2.00 | $2.00 |
| Output / 1M tokens | $6.00 | $6.00 |
| Context window | 2M | 2M |
| Parameters | — | — |
| Open weights | No | No |
| Released | Mar 2026 | Mar 2026 |
| LMArena (Chatbot Arena) Elo score | 1451 | — |
| LMArena WebDev Elo score | 1375 | — |
| LMArena Vision Elo score | 1263 | — |
FAQ
Is grok-4.20-beta-0309-reasoning or Grok 4.2 Fast Non Reasoning cheaper?
grok-4.20-beta-0309-reasoning and Grok 4.2 Fast Non Reasoning have comparable output pricing.
Which has the larger context window, grok-4.20-beta-0309-reasoning or Grok 4.2 Fast Non Reasoning?
Both models offer a similar context window.
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.