What is the difference between Claude Fable 5.1 and GPT-5.6 Terra?

Claude Fable 5.1 is developed by Anthropic while GPT-5.6 Terra is developed by OpenAI. Claude Fable 5.1 has a 1.0M token context window vs GPT-5.6 Terra's 1.1M. 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 GPT-5.6 Terra?

It depends on your use case. Claude Fable 5.1 and GPT-5.6 Terra 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 GPT-5.6 Terra?

Claude Fable 5.1 costs $10/M input tokens and GPT-5.6 Terra costs $2.5/M input tokens. GPT-5.6 Terra is $7.50/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 GPT-5.6 Terra on Rival?

This page shows a side-by-side comparison of Claude Fable 5.1 and GPT-5.6 Terra 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

Claude Fable 5.1vsGPT-5.6 Terra

GPT-5.6 Terra is cheaper than Claude Fable 5.1 at $2.5/M vs $10/M input tokens.

Claude Fable 5.1 and GPT-5.6 Terra compared across 10 shared prompts
Spec	Claude Fable 5.1	GPT-5.6 Terra
Input price	$10/M tokens	$2.5/M tokens
Output price	$50/M tokens	$15/M tokens
Context window	1.0M tokens	1.1M tokens
Weights	Closed	Closed
Free API (OpenRouter)	No	No
Released	Sep 2026	Jul 2026