Claude Fable 5 vs Claude Opus 4.8

Anthropic's Claude Fable 5 against Anthropic's Claude Opus 4.8 — price, context and what each is best at. Both are available through one OpenAI-compatible API.

AnyModel — you pay	Claude Fable 5	Claude Opus 4.8
Vendor	Anthropic	Anthropic
Input / 1M	$0.8	$0.4
Output / 1M	$0.8	$0.4
Context	1M	1M
Best for	Hardest problems	Architecture

Claude Fable 5

Anthropic's Mythos-class tier above Opus — #1 on our AI Arena.

Claude Fable 5 is the first model of Anthropic's Claude 5 family — a Mythos-class tier that sits above Opus in capability. It tops our agentic AI Arena ranking and comes with a 1M-token window. Vendor list price is $10/$50 per 1M.

More about Claude Fable 5 →

Claude Opus 4.8

The current Opus — Anthropic's agentic-coding flagship.

Claude Opus 4.8 leads the Claude 4 line on nuanced reasoning, agentic coding and careful long-form writing, now with a 1M-token context window. The go-to when output quality matters more than cost.

More about Claude Opus 4.8 →

Quick take: Claude Opus 4.8 is cheaper on output tokens ($0.4 vs $0.8 per 1M). Compare their strengths and context for your task; you can switch the model id at any time.

FAQ

Which is cheaper, Claude Fable 5 or Claude Opus 4.8?

Claude Opus 4.8 is cheaper on output tokens ($0.4 vs $0.8 per 1M).

Which has a larger context window, Claude Fable 5 or Claude Opus 4.8?

Claude Fable 5: 1M; Claude Opus 4.8: 1M.