Claude Fable 5 vs GPT-5.5

Anthropic's Claude Fable 5 against OpenAI's GPT-5.5 — price, context and what each is best at. Both are available through one OpenAI-compatible API.

AnyModel — you pay	Claude Fable 5	GPT-5.5
Vendor	Anthropic	OpenAI
Input / 1M	$0.8	$0.05
Output / 1M	$0.8	$0.05
Context	1M	1M
Best for	Hardest problems	Complex coding

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.

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GPT-5.5

OpenAI's flagship for coding, agents and research-grade reasoning.

GPT-5.5 is OpenAI's top general-purpose model and the engine behind modern Codex: state-of-the-art coding, computer use and multi-step reasoning with a ~1M-token window. The default pick when you want one model that handles everything.

More about GPT-5.5 →

Quick take: GPT-5.5 is cheaper on output tokens ($0.05 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 GPT-5.5?

GPT-5.5 is cheaper on output tokens ($0.05 vs $0.8 per 1M).

Which has a larger context window, Claude Fable 5 or GPT-5.5?

Claude Fable 5: 1M; GPT-5.5: 1M.