Claude Fable 5.1 vs Gemini 3.1 Pro

Pyyan / Compare / Claude Fable 5.1 vs Gemini 3.1 Pro

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Language Models · verified 2 Sept 2026

Claude Fable 5.1Anthropiccurrent

Gemini 3.1 ProGooglecurrent

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Specification	Claude Fable 5.1	Gemini 3.1 Pro
Summary	Same price as Fable 5, and cache reads cost a quarter of what they did.	Best for very large multimodal context.
Context	1M	1M
Input ($/Mtok)	$10	—
Output ($/Mtok)	$50	—
Licence	Proprietary	Proprietary
Max output	128K	—
Parameters	Not published	—
Released	1 Sep 2026	—
Model ID	claude-fable-5-1	—
Category	Language Models	Language Models
Official	—	Google ↗

Highlighted rows are where these differ.

Matches or beats Fable 5 at low and medium effort, and pulls clear at high effort
Cache reads cut to 25% of the old price, so re-reading a long context got much cheaper
Identical model to Mythos 5.1 underneath; the difference is the safeguards

Best for coding and long-running work.

Best for long documents.