---
title: "Claude Fable 5.1 — LLM-TEST.com"
url: /models/claude-fable-5-1/
canonical_url: https://llm-test.com/models/claude-fable-5-1/
language: en
type: model
summary: "Anthropic's premium top-end model, built for the hardest reasoning, long-horizon agentic work and high-stakes writing where quality matters more than cost. Sits above Opus as the flagship of the Claude 5 family."
last_updated: "2026-11-05"
---

# Claude Fable 5.1

_Anthropic · Flagship_

Anthropic's premium top-end model, built for the hardest reasoning, long-horizon agentic work and high-stakes writing where quality matters more than cost. Sits above Opus as the flagship of the Claude 5 family.

## At a glance

- Released: Oct 10, 2026
- Provider: Anthropic
- Context window: 1,000,000 tokens
- Max output: 128,000 tokens
- Modalities: Text + image → text
- Knowledge cutoff: July 2026
- API model ID: `claude-fable-5-1`
- License: Proprietary (API only)

## Pricing

- Standard: $10 input / $50 output per 1M tokens
- Batch: $5 input / $25 output per 1M tokens
- Example: a 1,500-token prompt + 650-token answer ≈ $0.048 (standard)

## What's new vs Claude Fable 5 (May 2026)

- Higher reliability on long multi-step agent runs
- Sharper nuance and consistency in long-form writing
- Larger effective context with steadier recall across it
- Premium pricing, the costliest tier in the lineup
- Higher latency than lighter Claude models

## Best use cases

- **High-stakes reasoning** — Tackles complex analysis and planning where a wrong answer is expensive.
- **Long-horizon agents** — Drives multi-hour agentic workflows with many tools and steps.
- **Premium writing** — Produces polished, voice-consistent long-form copy and editing.

## Strengths

- Top-tier reasoning quality
- Strong long-context recall
- Excellent writing and nuance
- Reliable tool use

## Limitations

- Most expensive option
- Slower than fast tiers

## Where to get access

- Consumer app: Claude apps (web, macOS, Windows, iOS, Android) — https://claude.ai
- API: the Anthropic Console — https://console.anthropic.com
- Also available: Amazon Bedrock and Google Vertex AI
- Docs: https://docs.anthropic.com

Full comparison and live pricing: https://llm-test.com/ · directory: https://llm-test.com/models/