Claude Fable 5.1 vs 
Mercury 2.5 Preview
Mercury 2.5 Preview is cheaper than Claude Fable 5.1 at $0.04/M vs $10/M input tokens.
Pokémon Battle UI Recreation
Pokémon battle screen you can actually click. One HTML 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: bigger model tier, bigger context window, major provider backing. Mercury 2.5 Preview costs 333x less per token.
| Spec | Claude Fable 5.1 | Mercury 2.5 Preview |
|---|---|---|
| Input price | $10/M tokens | $0.04/M tokens |
| Output price | $50/M tokens | $0.15/M tokens |
| Context window | 1.0M tokens | 260K tokens |
| Weights | Closed | — |
| Free API (OpenRouter) | No | No |
| Released | Sep 2026 | Aug 2026 |
| At 10M a month | $100 | $0.40 |
Input tokens at list price. No caching, no batch discount.
Where to run it
Mercury 2.5 Preview1 host
Per million tokens. Prices and uptime via OpenRouter, checked 13 Oct 2026.
Common questions
What is the difference between Claude Fable 5.1 and Mercury 2.5 Preview?
Claude Fable 5.1 is developed by Anthropic while Mercury 2.5 Preview is developed by Inception. Claude Fable 5.1 has a 1.0M token context window vs Mercury 2.5 Preview's 260K. 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 Mercury 2.5 Preview?
It depends on your use case. Claude Fable 5.1 and Mercury 2.5 Preview 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 Mercury 2.5 Preview?
Claude Fable 5.1 costs $10/M input tokens and Mercury 2.5 Preview costs $0.04/M input tokens. Mercury 2.5 Preview is $9.96/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 Mercury 2.5 Preview on Rival?
This page shows a side-by-side comparison of Claude Fable 5.1 and Mercury 2.5 Preview 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
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Same lab, same size, long tail
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