Anthropic'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.
- Step-change over Opus 4.8 for agentic coding, deep reasoning, and long-horizon autonomous work.
- 1M token context window (default and maximum) with 128K max output tokens.
- Adaptive thinking on by default with configurable output effort (low through max).
- Full tool support including web search, web fetch, code execution, and JSON mode.
- Pricing is $5.00 per 1M input tokens and $25.00 per 1M output tokens.
Web Search
Search the web for current info.
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 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.
Claude Opus 4.8Anthropic's most capable model released May 2026. Hybrid reasoning model with a 1M token context window, stronger across coding, agentic tasks, and professional work over Opus 4.7. Features adaptive thinking via the effort parameter (defaults to high). Knowledge cutoff January 2026.