Claude Fable Latest

Claude Fable 5.1

Claude Fable 5.1 improves on Fable 5 across agentic coding, long-running workflows, front-end and visual code generation, finance, analysis, and knowledge work, with more concise plans and summaries. Anthropic retains prompts and outputs for 30 days; Zero Data Retention is not available.

Claude Fable 5

Anthropic Claude Fable 5 for long-running coding, research, and knowledge-work tasks. Anthropic retains prompts and outputs for 30 days under its Covered Models policy; Zero Data Retention is not available.

Claude Haiku 5.5

Claude Haiku 5.5 is Anthropic's fastest and most capable small model, designed for high-volume, cost-sensitive tasks such as summaries, classification, coding assistance, and live customer support. It delivers major gains over Haiku 4.5 while costing around 75% less to run.

Claude Sonnet 5.5

Claude Sonnet 5.5 handles everyday coding, tool-based workflows, visual analysis, and polished writing with a 1M-token context window. This version skips up-front thinking and can reason between tool calls for faster responses; use Thinking for deeper planning and complex problems.

Claude Sonnet 5.5 Thinking

Claude Sonnet 5.5 with adaptive thinking for complex coding, multi-step tool use, visual analysis, and detailed planning. Supports a 1M-token context window and five reasoning effort levels, with stronger thinking available when a task needs it.

Claude Opus 5.5

Claude Opus 5.5 is Anthropic's flagship model for agentic coding, computer use, complex knowledge work, and long-running tasks, with improved efficiency and more natural communication.