Claude Sonnet 4
by Anthropic
Balanced hybrid reasoning model released May 2025, excelling in coding with 72.7% SWE-bench performance. Features dual modes for instant responses or extended thinking, making it ideal for practical AI applications requiring both speed and intelligence.
- Hybrid reasoning model with instant responses and extended thinking modes for optimal task handling
- State-of-the-art coding performance achieving 72.7% on SWE-bench with enhanced instruction following
- Superior codebase navigation and multi-file editing with 65% reduction in shortcut behavior
- Enhanced steerability and precision for complex implementations with improved tool integration
- Balanced performance and efficiency ideal for user-facing assistants and high-volume tasks
Web Search
Search the web for current info.
Extended Thinking
Enhanced reasoning for complex tasks.
Web Fetch
Fetch and read full content from any URL.
Code Execution
Run Python & Bash code in a sandbox.
JSON Mode
Output responses in valid JSON format.
Model Information
Supported Formats
Claude Fable 5Anthropic's most capable widely released model, for the most demanding reasoning and long-horizon agentic work. Thinking is always on with a 1M token context window (also the maximum) and 128K max output. Priced above the Opus tier for the highest capability ceiling in the Claude lineup.
Claude Opus 5Anthropic's successor to Opus 4.8 for complex agentic coding and enterprise work. Strongest on deep reasoning, agentic and long-horizon work, and test-time compute scaling, at half the cost of Claude Fable 5. Thinking is on by default with a 1M token context window and 128K max output.
Claude Sonnet 5Best combination of speed and intelligence in the Sonnet tier, delivering near-Opus quality on coding and agentic work. Successor to Sonnet 4.6 with adaptive thinking on by default, a 1M token context window, and 128K max output.