What is the difference between Aurora Alpha and Claude Fable 5.1?

Aurora Alpha is developed by OpenRouter while Claude Fable 5.1 is developed by Anthropic. Aurora Alpha has a 128K token context window vs Claude Fable 5.1's 1.0M. You can compare their actual outputs across 10 challenges on Rival to see how they differ in practice.

Which is better, Aurora Alpha or Claude Fable 5.1?

It depends on your use case. Aurora Alpha and Claude Fable 5.1 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 Aurora Alpha cost compared to Claude Fable 5.1?

Aurora Alpha costs $0/M input tokens and Claude Fable 5.1 costs $10/M input tokens. Aurora Alpha is $10.00/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 Aurora Alpha and Claude Fable 5.1 on Rival?

This page shows a side-by-side comparison of Aurora Alpha and Claude Fable 5.1 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.

Updated Sep 2026

Aurora AlphavsClaude Fable 5.1

Aurora Alpha is cheaper than Claude Fable 5.1 at $0/M vs $10/M input tokens.

Aurora Alpha and Claude Fable 5.1 compared across 10 shared prompts
Spec	Aurora Alpha	Claude Fable 5.1
Input price	Free	$10/M tokens
Output price	Free	$50/M tokens
Context window	128K tokens	1.0M tokens
Weights	—	Closed
Free API (OpenRouter)	No	No
Released	Feb 2026	Sep 2026

Our Verdict

Claude Fable 5.1

Aurora AlphaRunner-up

Not enough votes to call it. On the specs, Claude Fable 5.1 has the edge: bigger model tier, newer, bigger context window, major provider backing.

Slight edge

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

Aurora Alpha

Input

$0.000

Output

$0.000

Claude Fable 5.1

Input

$10.00

Output

$50.00

Where to run it

4 hosts

Aurora Alpha

No hosts listed on OpenRouter.

Claude Fable 5.14 hosts

HostInOutContextUptime

Amazon Bedrock$10.00 in$50.00 out1M—Anthropic$10.00 in$50.00 out1M99.1% up Azure AI Foundry$10.00 in$50.00 out1M99.1% up Google Vertex AI$10.00 in$50.00 out1M99.8% up

Per million tokens. Prices and uptime via OpenRouter, checked 16 Sep 2026.

Research

What we learned reading every model

FAQ

Common questions

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Cost per 1M tokens

4 hosts

What we learned reading every model

Common questions

What is the difference between Aurora Alpha and Claude Fable 5.1?

Which is better, Aurora Alpha or Claude Fable 5.1?

How much does Aurora Alpha cost compared to Claude Fable 5.1?

How can I compare Aurora Alpha and Claude Fable 5.1 on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages

Cost per 1M tokens

4 hosts

What we learned reading every model

Common questions

What is the difference between Aurora Alpha and Claude Fable 5.1?

Which is better, Aurora Alpha or Claude Fable 5.1?

How much does Aurora Alpha cost compared to Claude Fable 5.1?

How can I compare Aurora Alpha and Claude Fable 5.1 on Rival?

More comparisons

Against the newest arrivals

Same lab, same size, long tail

Model pages