Fable 5.1 leads in external benchmarks, while Mythos 5.1 is designed to handle more cyber tasks with loosened safety mechanisms.

Claude Fable 5.1 is now available to the public, while Mythos 5.1 is limited to select customers through Anthropic’s verification programmes. Both use the same core system but have different safety ...

Anthropic's Claude Fable 5.1 and OpenAI's GPT-6 Astra widen the proprietary AI lead in web development to nearly 1,800 points over open-source ...

Singapore - September 29, 2026 - PRESSADVANTAGE - ZenMux has added Claude Fable 5.1 to its model catalog, giving ...

Google’s Gemini 4 Argon has drawn attention for its standout performance in multi-step reasoning and extended coding tasks, ...

Mythos 5.1 is also launching in Project Glasswing.

Anthropic’s Claude Fable 5.1 lowers agent costs, while restricted Mythos 5.1 offers more permissive safeguards for approved research work.

In Anthropic’s world, Fable is Claude’s most capable model. Haiku, Sonnet, and Opus are the small, medium, and large models below Fable. “Claude Fable 5.1 sets a new standard on coding, knowledge work ...

It's only the first day of September 2026, but the month and fall season are already off to the races in AI land, as Anthropic has just released its latest and most powerful large language models yet ...

Anthropic withheld its advanced Claude Mythos 5.1 model from the UK’s AISI, sparking concerns over growing US influence on private AI releases under Trump-era export controls.

OpenAI launched GPT-6 Astra, its latest flagship AI model, claiming advances in computer use, coding, cybersecurity and scientific reasoning. The model is rolling out to ChatGPT users and enterprise ...