Claude Fable 5.1 vs 
Grok 3
Claude Fable 5.1 has a larger context window than Grok 3 (1.0M tokens vs 128K tokens).
Three.js 3D Game
Place buildings, then drive through the town you made. Three.js, one file.
Loading the build
Loading the build
Which answer wins?
Price and specs
Not enough votes to call it. On the specs, Claude Fable 5.1 has the edge: newer, bigger context window.
| Spec | Claude Fable 5.1 | Grok 3 |
|---|---|---|
| Input price | $10/M tokens | — |
| Output price | $50/M tokens | — |
| Context window | 1.0M tokens | 128K tokens |
| Weights | Closed | — |
| Free API (OpenRouter) | No | No |
| Released | Sep 2026 | Feb 2025 |
| At 10M a month | $100 | not listed |
Input tokens at list price. No caching, no batch discount.
Where to run it
Grok 3
No hosts listed on OpenRouter.
Per million tokens. Prices and uptime via OpenRouter, checked 13 Oct 2026.
Common questions
What is the difference between Claude Fable 5.1 and Grok 3?
Claude Fable 5.1 is developed by Anthropic while Grok 3 is developed by xAI. Claude Fable 5.1 has a 1.0M token context window vs Grok 3's 128K. You can compare their actual outputs across 9 challenges on Rival to see how they differ in practice.
Which is better, Claude Fable 5.1 or Grok 3?
It depends on your use case. Claude Fable 5.1 and Grok 3 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 9 challenges so you can judge which fits your needs best.
How can I compare Claude Fable 5.1 and Grok 3 on Rival?
This page shows a side-by-side comparison of Claude Fable 5.1 and Grok 3 across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.
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