PyyanThe AI Index

Pyyan / Compare / Gemini 3.8 Live Extended Thinking vs Claude Fable 5.1

Gemini 3.8 Live Extended Thinking vs Claude Fable 5.1

2 of 5

Language Models · verified 16 Sept 2026

Gemini 3.8 Live Extended ThinkingGooglecurrent
Claude Fable 5.1Anthropiccurrent
3 slots left
SpecificationGemini 3.8 Live Extended ThinkingClaude Fable 5.1
SummaryTop of the speech to speech board, and it reasons out loud while it gets there.Same price as Fable 5, and cache reads cost a quarter of what they did.
ContextNot published1M
Input ($/Mtok)$0.75$10
Output ($/Mtok)$4.5$50
LicenceProprietaryProprietary
Max outputNot published128K
ParametersNot publishedNot published
Released15 Sep 20261 Sep 2026
Model IDgemini-3.8-live-extended-thinkingclaude-fable-5-1
CategoryLanguage ModelsLanguage Models
OfficialGoogle ↗—

Highlighted rows are where these differ.

Gemini 3.8 Live Extended Thinking

  • First on the Artificial Analysis Speech to Speech Quality Index at 82.6
  • 68.6% on tau-Voice and 97.7% on Big Bench Audio, both reported by Google
  • Speaks while it reasons, with cues such as let me check that

Best for hard tasks done by voice.

Full spec sheet →

Claude Fable 5.1

  • 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.

Full spec sheet →