Claude Fable 5.2 arrives with faster output and a lower price
Anthropic released Claude Fable 5.2 and Claude Mythos 5.2 on Monday, November 9, and Fable 5.2 is available to all users today. Anthropic says the new models generate output up to 30 percent faster than the 5.1 versions and cost less for developers to run.
Fable and Mythos are the same model
Fable and Mythos sit above Haiku, Sonnet and Opus in Claude's lineup. Anthropic says they share the same underlying model. The difference is safeguards: Fable blocks most high-risk cybersecurity and research biology tasks, which lets Anthropic offer it to everyone. Mythos drops those blocks and is limited to vetted organizations that apply through Anthropic's Cyber Verification and Life Sciences Verification programs.
Anthropic says version 5.2 improves coding, reasoning and vision. It also says testers found the models communicate more clearly than earlier Fable and Mythos releases.
Price and speed
Fable 5.2 and Mythos 5.2 cost $8 per million input tokens and $40 per million output tokens. Anthropic describes that as a lower price than the 5.1 models.
An optional fast mode speeds up token generation by up to 2.5 times, according to Anthropic. It costs $16 per million input tokens and $80 per million output tokens and works in Claude Code, the Claude Platform, Google Cloud and Microsoft Foundry. Mythos fast mode is limited to members of the verification programs.
What Anthropic's benchmarks show
In Anthropic's own testing, Fable 5.2 scored above Opus 5.5 on almost every benchmark it published. A few results from the company's table:
- Agentic coding: 49.1 percent on FrontierCode 2.0, up from 32.4 percent for Fable 5.1 and ahead of 42.8 percent for GPT-6 Astra.
- Computer use: 89.3 percent on OSWorld 2.1, compared with 83.5 percent for Fable 5.1.
- Robotics: 64.9 percent on the RoboDojo simulation, more than double Fable 5.1's 27.6 percent.
Anthropic also says a team of about 1,000 Fable 5.2 agents formalized the proof of Fermat's Last Theorem in 30 hours, compared with 11 days for the company's first formalization, and that the model solved two open problems in black hole physics. Both results come from Anthropic's own reporting.
On safety, Anthropic says Fable 5.2 triggered about 55 percent fewer blocks than Fable 5.1 in early testing across claude.ai, Claude Code and Cowork. When a request is blocked, Claude falls back to an older model: Opus 4.8 for cybersecurity and Opus 5 for biology.
What it means for you
Fable 5.2 is available now on all platforms, including Amazon Web Services, Google Cloud and Microsoft Azure. Developers can call it as claude-fable-5-2.
If you pay for Claude, Anthropic is giving subscribers on eligible paid plans extra Fable usage this week. Pro subscribers and standard Team seats can use Fable for up to 50 percent of their weekly usage limits, and plans that include Fable get one to three Fable usage resets depending on how long they've subscribed.
For most coding and knowledge tasks, Anthropic's own advice is to start with Claude Opus 5.5, which it calls its "strongest daily driver," and drop down to Sonnet 5.5 or Haiku 5.5 when a job is simpler. Fable is aimed at the most ambitious open-ended technical work.