WhichAI / Compare / Claude Fable 5 vs Claude Opus 4.8

Claude Fable 5vsClaude Opus 4.8

Claude Fable 5 scores higher on the September 8, 2026 index. Full context below: price, context window, strengths and honest limits. Verified September 8, 2026.

Claude Fable 5

Claude Opus 4.8

Provider

AA index

62.1

57.3

Released

n/a

Context

Price $/1M

$10 / $50

$5 / $25

Access

Claude Pro / Max plans (usage credits since July 7) · API $10/$50 per 1M tokens

Claude Pro $20/mo · API

n/a = not published or not yet verified. Scores marked ~ are WhichAI estimates and should not be compared 1:1 with measured scores.

In one line each

Claude Fable 5: Anthropic's newest flagship (Mythos-class) - tops the AA index at max effort and leads creative-writing boards for voice, subtext and character work; briefly export-controlled, now globally available.

Claude Opus 4.8: The leader on real-repo coding when it shipped (SWE-bench Pro 69.2%) and still a serious software workhorse, now at a price its successors undercut. Worth choosing deliberately rather than by default.

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