Sonnet 5 is a Chrome extension that brings Anthropic’s latest AI model, Claude Sonnet 5, directly to your browser. It offers instant chat without setup or API keys, allowing you to ask questions, get explanations, brainstorm ideas, and write or rewrite content. The extension also lets you paste text from any page for translation, summarization, or explanation. Ideal for writers, students, developers, and professionals seeking a fast AI assistant.