What is Claude?
Claude is an AI assistant built by Anthropic, designed to help with writing, analysis, coding, research, and complex reasoning. It is available as a web app, mobile app, desktop tool, and via API — making it accessible to individuals, developers, and enterprise teams alike.
Unlike many AI tools built primarily around speed or raw capability, Claude is developed with a focus on safety and reliability. Anthropic trains Claude using a technique called Constitutional AI, which encodes a set of guiding principles directly into how the model reasons and responds — aiming to make it honest, helpful, and less likely to cause harm.
What Can Claude Do?
Claude handles a wide range of everyday and professional tasks:
- Writing — Drafts emails, reports, blog posts, summaries, and long-form content with adjustable tone and style
- Coding — Writes, explains, and debugs code across languages; builds apps even for non-developers
- Analysis — Interprets uploaded spreadsheets, PDFs, images, and charts
- Research — Searches the web and returns cited, structured answers on complex topics
- Reasoning — Works through multi-step problems, plans, and decisions with extended thinking
Claude Models
Claude comes in three sizes, balancing speed, capability, and cost:
| Model | Best For |
|---|---|
| Haiku | Fast, lightweight tasks; high-volume applications |
| Sonnet | Everyday work; the best balance of speed and quality |
| Opus | Complex reasoning, coding, and research at the highest capability level |
The current generation is the Claude 4.6 family, with Sonnet 4.6 and Opus 4.6 as the flagship models. All models support a context window of up to 1 million tokens — large enough to process entire codebases or document libraries in a single session.
How to Access Claude
| Product | What It Is |
|---|---|
| Claude.ai | Web, mobile, and desktop chat interface |
| Claude API | Direct programmatic access for developers |
| Claude Code | Command-line tool for agentic coding workflows |
| Claude Cowork | Desktop app for file and task automation (non-developers) |
| Claude in Chrome | Browser extension for web-based tasks |
Plans range from a free tier to Pro ($20/month), Max ($100–$200/month), and Team ($25/user/month). Developers using the API pay per token, with batch and caching discounts available.
Why Claude?
A few things distinguish Claude from other AI assistants:
- Safety-first design — Constitutional AI training makes Claude's behavior more predictable and principled
- Long context — 1M token windows enable use cases other models can't handle
- Ad-free — Anthropic has committed to keeping Claude products free of advertising
- Honest by design — Claude is trained to say when it doesn't know something, rather than confidently guessing
What's Next
The pages in this section walk through how to get the most out of Claude — from writing effective prompts to using advanced features like Projects, Memory, and Skills.