The AI assistant built for serious thinking, coding, and complex work
Claude is an AI assistant built by Anthropic using Constitutional AI — a training approach that prioritizes safety, honesty, and helpfulness. Unlike general chatbots, Claude is designed for deep reasoning, nuanced writing, long-document analysis, and autonomous coding tasks. The model lineup — Haiku (fast and lightweight), Sonnet (balanced performance), and Opus (maximum reasoning) — lets users choose the right power level for each job. Claude 3.5 Sonnet outperforms GPT-4o on graduate-level reasoning benchmarks (GPQA), undergraduate knowledge (MMLU), and coding challenges (HumanEval), solving 64% of agentic coding tasks versus 38% for the prior generation. Standout capabilities include one of the largest context windows available at 200,000 tokens — enough to process entire codebases or books in a single session — plus vision and image analysis, multi-step agentic task execution, and Claude Code for autonomous software development. Claude integrates natively with Chrome, Slack, Excel, and PowerPoint, and is available on AWS Bedrock and Google Cloud Vertex AI for enterprise deployments. For API users, access starts at $3 per million input tokens and $15 per million output tokens for Sonnet 4.6. The free tier gives access to Claude.ai with limited daily usage.