Claude (family)

Anthropic's flagship LLM family — Claude 1, 2, 3 (Haiku/Sonnet/Opus tiers), Claude 3.5/3.7, Claude 4 — known for long context, strong coding, and rigorous safety training.

Claude is Anthropic's flagship language model family, named after Claude Shannon (the father of information theory). The line: Claude 1 (2023), Claude 2, Claude 3 (March 2024, introducing the three-tier Haiku/Sonnet/Opus split), Claude 3.5 Sonnet, Claude 3.7 Sonnet (with extended thinking), Claude 4 series. It matters because Claude is the main alternative to GPT for many serious developer use cases. It's especially popular for coding (Claude Code, integration into Cursor and other editors), long-document analysis, agentic workflows, and applications where the developer values Anthropic's safety profile and Constitutional AI training. Many engineering teams report Claude as their preferred model for code-heavy work. The three-tier structure is influential: Haiku (fast, cheap, lightweight), Sonnet (balanced — usually the workhorse), Opus (most capable but slowest and most expensive). Each tier serves a different cost/capability point. Claude is available via Anthropic's API, AWS Bedrock, Google Cloud Vertex, Microsoft Azure (in some regions), and the Claude.ai consumer chat product. Like GPT, Claude is closed source — you can only use it through Anthropic or its cloud partners. The Claude family has consistently scored at or near the top of coding benchmarks like SWE-bench. Related: Anthropic, Constitutional AI, GPT family, frontier model.