Claude Fable 5, the Anthropic model in numbers

Overview

Released on June 9, 2026, Claude Fable 5 is one of the 12 Anthropic models tracked on this site. It is a closed model: you access it through an API, from Anthropic or one of the 46 providers listed on models.dev. It has a reasoning mode: it can "think" before answering, which helps with multi-step problems but uses more tokens, and therefore more money. That makes it 4 months old as of October 22, 2026.

We file it under frontier models (24 models in this category on the site).

What do independent benchmarks say?

According to results published by Epoch AI (checked on October 22, 2026), Claude Fable 5 has a capability index of 90.8 out of 100, computed on 5 benchmarks from our basket.

That puts it at #8 in our weekly model ranking.

• GPQA Diamond (PhD-level science questions): 85.9% — the best tracked model, Gemini 4 Argon, reaches 96.4%
• OTIS Mock AIME (competition mathematics problems): 100% — the best tracked model, GPT-5.5 Pro, reaches 100%
• FrontierMath (very hard research-level mathematics): 87% — the best tracked model, GPT-6 Astra, reaches 93.7%
• FrontierCode (advanced programming tasks): 53.5% — the best tracked model, Claude Opus 5.5, reaches 54.6%

What it can do

Its context window reaches 1,000,000 tokens, roughly 1,500 pages of text at 500 words per page: enough to load a whole book or a mid-sized codebase. A single answer can run to 50,000 tokens.

It accepts as input: text, image and PDF. Its knowledge stops at January 31, 2026: beyond that, it needs web search or your documents.

It can call tools (functions, APIs), which makes it a possible foundation for an AI agent.

How much does Claude Fable 5 cost?

Claude Fable 5 costs $10 per million input tokens and $50 per million output tokens (median of 46 providers, checked on October 22, 2026).

To put it in perspective: reading 20,000 tokens (about thirty pages) and writing 2,000 costs roughly $0.30; a thousand of those tasks, $300.

That is 3.4 times the median output price of frontier models ($14.5).

To estimate your own budget, use the agent cost calculator.

What is it good for?

Given its category, Claude Fable 5 is mainly aimed at hard tasks where quality matters more than cost: deep reasoning, complex code, long analyses.

Its FrontierCode result (53.5%, above the median of tracked models) makes it a serious candidate for coding agents.

Its very large context window makes it worth considering for analysing large sets of documents in a single request.

Before adopting it, test it on your own examples: benchmarks measure standard tasks, not your job.

What could replace it?

In the same category, the models closest to Claude Fable 5 are:

• GPT-6.1 Sol (OpenAI, index 92.1) — see the comparison
• GPT-6 Sol (OpenAI, index 89.2) — see the comparison
• Claude Fable 5.1 (Anthropic, index 92.6) — see the comparison
• Claude Opus 5 (Anthropic, index 92.7) — see the comparison