Anthropic Claude Fable 5, the most powerful and most intelligent Claude model, a new tier above Opus. State-of-the-art deep reasoning, long-horizon autonomous work, and code understanding and generation, surpassing Opus 4.8 on the hardest analyses, large refactors, and complex system design. Supports very long context for whole-codebase or multi-document analysis. Premium pricing (about twice Opus 4.8); reserve it for the most demanding tasks and use Opus or Sonnet for daily work. If you need to search the web for information, please turn on the "Web Search" switch. Maximum context window (input and output combined): about 1,000,000 tokens. Maximum output per reply: about 64,000 tokens (model reasoning, if any, counts toward this limit). Maximum total upload size per request: 256MB (all files and message content combined). Accepted document formats: pdf, docx, xlsx, pptx, txt, csv (file content is provided to the model as extracted text). Accepted image formats: gif, jpeg, jpg, png, webp. Animated GIF images are analyzed using only the first frame. Maximum number of images: 600. When uploading more than 20 images, each side must be at most 2,000 pixels. Maximum size per image: 10MB (base64-encoded). Maximum total image size per message: 20MB (text and history share the same request size limit; uploads close to the limit may still be rejected). Image dimensions: 200 to 8,000 pixels per side. Output content formats: Text/Image This module supports continuous conversations. AI can make mistakes. Please verify important information.