Claude Fable 5.1 vs 
OpenAI o3
Claude Fable 5.1 is the newer model, released after OpenAI o3.
Pokémon Battle UI Recreation
Pokémon battle screen you can actually click. One HTML file.
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Which answer wins?
Price and specs
| Spec | Claude Fable 5.1 | OpenAI o3 |
|---|---|---|
| Input price | $10/M tokens | $10/M tokens |
| Output price | $50/M tokens | $40/M tokens |
| Context window | 1.0M tokens | — |
| Weights | Closed | Closed |
| Free API (OpenRouter) | No | No |
| Released | Sep 2026 | Apr 2025 |
| At 10M a month | $100 | $100 |
Input tokens at list price. No caching, no batch discount.
Where to run it
OpenAI o31 host
Per million tokens. Prices and uptime via OpenRouter, checked 12 Oct 2026.
Common questions
What is the difference between Claude Fable 5.1 and OpenAI o3?
Claude Fable 5.1 is developed by Anthropic while OpenAI o3 is developed by OpenAI. You can compare their actual outputs across 10 challenges on Rival to see how they differ in practice.
Which is better, Claude Fable 5.1 or OpenAI o3?
It depends on your use case. Claude Fable 5.1 and OpenAI o3 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 10 challenges so you can judge which fits your needs best.
How much does Claude Fable 5.1 cost compared to OpenAI o3?
Claude Fable 5.1 costs $10/M input tokens and OpenAI o3 costs $10/M input tokens. OpenAI o3 is $0.00/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.
How can I compare Claude Fable 5.1 and OpenAI o3 on Rival?
This page shows a side-by-side comparison of Claude Fable 5.1 and OpenAI o3 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.
More comparisons
Against the newest arrivals
- Claude Fable 5.1 vs GPT-4 TurboLanded Oct 2026
- OpenAI o3 vs Step 5 PreviewLanded Oct 2026
- Claude Fable 5.1 vs Claude Haiku 5.5Landed Oct 2026
- OpenAI o3 vs Ling 3.1 FlashLanded Oct 2026
- Claude Fable 5.1 vs Mistral Large 4Landed Oct 2026
- OpenAI o3 vs GPT-6.1 SolLanded Sep 2026
- Claude Fable 5.1 vs Claude Sonnet 5.5Landed Sep 2026
- OpenAI o3 vs Solar Mini 4Landed Sep 2026
Same lab, same size, long tail
- Claude Fable 5.1 vs Claude Opus 5.5Same lab
- Claude Fable 5.1 vs Claude Opus 5Same lab
- OpenAI o3 vs OpenAI o4-miniVersion compare
- OpenAI o3 vs GPT-4 TurboSame lab
- OpenAI o3 vs MiniMax M3New provider
- Claude Fable 5.1 vs Mistral LargeNew provider
- Claude Fable 5.1 vs Mistral Large 2New provider
- Claude Fable 5.1 vs Mistral Large 3 2512Same size
