Claude

Claude is Anthropic's conversational assistant. The Claude 5 model family includes Opus 5 (the most capable), Sonnet 5 (a balance of performance and cost) and Haiku 4.5 (fast and light), plus Fable 5.1. Claude is known for writing quality, reasoning, long-document analysis and instruction-following.

Anthropic's assistant, valued for writing and long documents. See also: ChatGPT · Claude Code · Which AI to choose, and our feature on artificial intelligence.

01 — What it is

Claude, explained

Claude is Anthropic's conversational assistant. The Claude 5 model family includes Opus 5 (the most capable), Sonnet 5 (a balance of performance and cost) and Haiku 4.5 (fast and light), plus Fable 5.1. Claude is known for writing quality, reasoning, long-document analysis and instruction-following.

02 — Strengths

Where Claude stands out

• Careful, consistent writing with a nuanced tone, strong across languages.
• Large context window: analyzing reports, contracts, entire codebases.
• "Artifacts" feature (documents and mini-apps produced alongside the chat) and connectors to tools.
• An approach centered on safety and faithfully following instructions.

03 — Limitations & precautions

What to keep in mind

• Like any model, it can be wrong: verify facts and figures.
• Free tier is limited in throughput and model access; the best models are paid.
• Availability by country varies depending on the plan.
• Data processed by a third party: sensitive use requires the right plan and verified settings.

04 — Access & pricing

How to access it

Free access with an account on the web and app, with usage limits. Paid plans (individual, team, enterprise) and developer access via API. Also available through third-party cloud platforms. Plans and versions evolve fast: check current pricing and capabilities on the official site.

05 — Professional use cases

Where Claude helps an organization

• Drafting and rewriting long documents, briefing notes.
• Analyzing contracts, reports, specifications.
• Code review and refactoring, explaining existing codebases.
• Internal assistant connected to a document base (with RAG).

06 — Frequently asked questions

Frequently Asked Questions

What are the Claude models?

The Claude 5 family: Opus 5 (the most capable), Sonnet 5 (balanced), Haiku 4.5 (fast), and Fable 5.1. Names and capabilities evolve — check Anthropic's site.

Is Claude free?

There's a limited free tier. Paid plans give more throughput, better models and data guarantees.

Claude for code?

Yes: it's known to be solid at reading and writing code, and there's a command-line tool, Claude Code.

07 — Resources & links

Where to go, concretely