# Anthropic — Introducing Claude Fable 5.1 and Claude Mythos 5.1

- Company: Anthropic (anthropic.com)
- Announced: 2026-09-01
- Category: new-model
- Coverage: 4 outlets
- Announcement: yes
- Group: models
- Source: https://www.anthropic.com/claude-fable-and-mythos-5-1
- Record: https://forck.live/items/7275-introducing-claude-fable-5-1-and-claude-mythos-5-1
- Subject: Claude
- Models affected: Claude Fable 5.1, Claude Mythos 5.1
- Pricing: cost an estimated 25% less than Fable 5 for typical workloads

Anthropic announces two new models: Claude Fable 5.1 (generally available) and Claude Mythos 5.1 (restricted access). They are the same model with different safeguards, offering improved performance in coding, knowledge work, and scientific research, with lower pricing and enhanced privacy and safety features.

## Evidence

Verbatim from https://www.anthropic.com/claude-fable-and-mythos-5-1:

> We're introducing Claude Fable 5.1 and Claude Mythos 5.1. They're the world's most advanced models for coding and knowledge work—and their research capabilities offer an early glimpse of how AI models will contribute to scientific progress.

## Around this story

Outlets this record can name and link:

- The Verge: https://theverge.com/ai-artificial-intelligence/987830/anthropic-claude-fable-mythos-5-1
- Moneycontrol — Anthropic launches Claude Fable 5.1 and Mythos 5.1 with improved coding, research capabilities and lower pricing: https://moneycontrol.com/technology/anthropic-launches-claude-fable-5-1-and-mythos-5-1-with-improved-coding-research-capabilities-and-lower-pricing-article-14020859.html
- Silicon Republic — Anthropic launches Claude Fable 5.1 and Mythos 5.1: https://siliconrepublic.com/machines/anthropic-launches-claude-fable-5-1-and-mythos-5-1
- The Deep View — In Fable 5.1, AI's cost war comes for Anthropic: https://thedeepview.com/articles/in-fable-5-1-ai-s-cost-war-comes-for-anthropic

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