Claude Fable 5: The Complete Guide for 2026
Everything you need to know about Claude Fable 5: what it is, how much it costs, where it is available, and how to start using it today.
TL;DR
On June 9, 2026, Anthropic announced Claude Fable 5, the first publicly available Mythos-class model, made safe for general use. It is state-of-the-art on nearly all tested capability benchmarks, especially long and complex tasks. Pricing is 10 dollars per million input tokens and 50 dollars per million output tokens, and the model is included free on Pro, Max, Team, and Enterprise plans from June 9 to June 22, 2026.
What Is Claude Fable 5?
Claude Fable 5 is Anthropic's most powerful generally available model ever. It was announced alongside Claude Mythos 5 on June 9, 2026. The two share the same underlying model, but Fable 5 ships with safeguards that make it appropriate for general use, while Mythos 5 lifts those safeguards in some areas for a restricted set of vetted organizations.
The headline result is coding: Fable 5 scores 80.3 percent on SWE-Bench Pro, compared to 69.2 percent for Claude Opus 4.8, 58.6 percent for GPT-5.5, and 54.2 percent for Gemini 3.1 Pro - roughly 11 points ahead of the next best model. It also posted the highest score among frontier models on Cognition's FrontierCode eval for code quality and efficiency. Andrej Karpathy called it "a major-version-bump-deserving step change forward" and noted that its benchmarks are "SOTA on everything by a margin".
Pricing and the Free Window
Fable 5 costs 10 dollars per million input tokens and 50 dollars per million output tokens. That is double Opus 4.8's 5 dollar and 25 dollar rates, but less than half the price of Claude Mythos Preview.
- June 9 to June 22, 2026: included free on Pro, Max, Team, and Enterprise plans
- From June 23, 2026: requires usage credits on those plans
- The Claude API: fully available at the standard rates above
Where You Can Use It
Beyond the Claude apps and the Claude API, Fable 5 is generally available on Amazon Bedrock and on GitHub Copilot, so teams already standardized on AWS or GitHub can adopt it without changing platforms. GitHub CPO Mario Rodriguez said: "What excites us most is the direction it points: a future where developers can hand increasingly ambitious work to agents."
What Makes It Different
Fable 5 maintains focus across millions of tokens of context. In an early test, Stripe used it to complete a 50-million-line Ruby codebase migration in one day - work the company estimated would have taken a team over two months. Its vision is state-of-the-art at extracting precise numbers from scientific figures and rebuilding web apps from screenshots, and it completed Pokemon FireRed using only vision, where earlier models needed helper tools.
Safety remains central: cybersecurity classifiers route triggered queries to Claude Opus 4.8 instead, safeguards trigger in under 5 percent of sessions on average, and more than 1,000 hours of external red-teaming found no universal jailbreaks.
How to Get Started
If you are on a paid Claude plan, just select Claude Fable 5 in the model picker before June 22 to try it free. Developers can call it through the Claude API immediately, or through Amazon Bedrock and GitHub Copilot.