Claude Fable 5 vs Mythos 5: What's The Difference And Why Is One Restricted?

OpenAI rival Anthropic has launched a new AI model called Claude Fable 5. The AI startup says it is its most capable public AI model so far and is built for complex coding, research, and enterprise work.Alongside Fable 5, Dario Amodei's company has also introduced Claude Mythos 5. While both models are based on the same technology, Mythos 5 is not available to everyone. It is currently being offered only to a small group of trusted organisations, security researchers, and government partners because of its advanced cybersecurity capabilities.If both models are built on the same tech, what makes them different and why is one being kept restricted? Let's find out.Claude Fable 5 vs Mythos 5 Claude Fable 5 is Anthropic's newest flagship AI model which

is developed to handle complex tasks that can continue for hours or even days. The model can plan large projects, write and test code, analyse huge amounts of information, and complete multi-step tasks with very little human supervision.Anthropic says Fable 5 can understand diagrams, charts, tables, PDFs, and other visual content. The model is created for software developers, researchers, enterprises, and organisations handling complex work.Fable 5 Brings Anthropic's Mythos AI To The Public, Minus The Risk "Claude Fable 5 is our most capable model for ambitious coding projects, including large migrations, complex implementations, and multi-day autonomous sessions. It can write its own tests to check its work, implement designs with high fidelity, and use vision to check outputs against goals," Anthropic said in a blog post.Claude Fable 5 is priced at $10 per million input tokens and $50 per million output tokens.On the other hand, Claude Mythos 5 is the more powerful version of the same model family. Anthropic describes it as having the strongest cybersecurity capabilities of any AI model currently available.According to Anthropic, Mythos 5 can identify software vulnerabilities, perform advanced security research and handle highly complex technical tasks. Because of these capabilities, access is currently limited through Anthropic's Project Glasswing programme and selected government partnerships.Basically, Mythos can do things that could potentially be misused if released widely.Why Is Mythos Restricted?The biggest reason is security. Anthropic believes Mythos is capable enough to discover critical vulnerabilities in software, operating systems, and online systems. While such capabilities can help improve cybersecurity, they could also be abused by bad actors. To reduce risks, the company is restricting access and carefully monitoring who can use the model.Anthropic Warns AI Could Soon Start Improving ItselfMeanwhile, Claude Fable 5 includes additional safeguards. If users attempt certain high-risk cybersecurity or biology-related tasks, requests may be automatically routed to a safer model version.Which One Will Most People Use?For most businesses, developers, and everyday users, Claude Fable 5 is the model they will interact with. It offers many of the same advanced reasoning, coding, vision, and agent capabilities as Mythos 5 while adding stronger safety protections.Mythos 5, on the other hand, is currently reserved for specialised cybersecurity research and government-backed projects.