Claude: a plain-English guide

What Claude is and who makes it

Claude is an AI assistant made by Anthropic, an American AI safety and research company based in San Francisco and founded by a group of former OpenAI researchers. Claude is both the name of the chat app and the name of the models behind it. You can ask it questions, have it draft or edit text, analyze long documents, write and review code, or work through a problem step by step.

Anthropic puts a lot of public emphasis on safety. It publishes the principles it uses to shape Claude's behavior, which it calls Claude's constitution, and it trains Claude to be helpful while avoiding harmful answers. In practice, Claude has a reputation for clear, natural writing and for following detailed instructions closely.

The Claude model family

Anthropic organizes its models in tiers that trade speed against capability. The tier names have stayed stable across generations, which makes them easier to follow than version numbers:

• Haiku is the smallest and fastest tier, built for quick, high-volume jobs such as summaries, classification and customer support.
• Sonnet balances speed and intelligence and suits most everyday work.
• Opus is the most capable mainstream tier, aimed at long-running coding and knowledge work.
• Fable is a newer top tier for the most demanding reasoning and long agent tasks. It is slower and more expensive to run.

As of October 2026, the current generation is numbered 5.5 for Opus, Sonnet and Haiku. All current Claude models accept text and images, can use tools, and handle very long inputs, so you can give them a whole report or a large part of a codebase at once. Claude models are closed: Anthropic does not publish their weights, and there is no official way to download and run Claude on your own computer.

What Claude is good at

• Writing and editing. Many writers like Claude's tone. It is good at keeping a consistent voice, tightening a draft and explaining why it changed something.
• Long documents. Contracts, research papers, meeting transcripts and manuals can be summarized, compared or questioned in one go.
• Coding. Claude is widely used by developers. Claude Code, Anthropic's coding tool for the terminal and code editors, can read a project, make changes across files and run commands with your approval.
• Following instructions. Detailed briefs, style guides and output formats tend to be respected, which helps with repeatable work.
• Building things in the chat. Artifacts let Claude create documents, diagrams, charts and small web apps in a side panel that you can edit and reuse.
• Research and connected work. Web search, a deeper Research mode on paid plans, projects for organizing files, memory, and connectors to tools such as Google Workspace or Slack.

Limits to keep in mind

Claude can be wrong. It may misread a source, get a date or number wrong, or invent a reference that sounds real. Treat its answers as a strong first draft, not a final authority, and check facts that matter. Our guide on fact-checking AI answers explains how.

Other limits are practical. The Free plan has tighter usage limits, which you notice sooner in long conversations or with big files. Features such as Claude Code, Research and the larger models are mostly part of paid plans. Claude is only offered in supported countries, so the official apps are not available everywhere. Claude can also be cautious and occasionally declines harmless requests that sound risky; rephrasing with more context usually helps.

How to use Claude officially

You can use Claude on the web at claude.ai, in desktop apps for Mac and Windows, and in the iOS and Android apps. Plans are Free, Pro and Max for individuals, and Team and Enterprise for organizations. Developers use the Claude API on Anthropic's platform, and Claude models are also offered through Amazon Bedrock, Google Cloud and Microsoft Foundry. Prices and limits change, so check Anthropic's pages before paying. The official link in the facts section of this page goes to Anthropic's Claude site.

Privacy notes

On consumer plans (Free, Pro and Max), you choose whether Anthropic may use your chats and coding sessions to train future models. The switch is in Settings, under Privacy, labelled "Help improve Claude". If it is on, new or resumed chats may be kept in de-identified form for up to five years for training. If you turn it off, new chats are not used for future training, though data already used in earlier training cannot be removed from existing models. Incognito chats are never used for training, even with the setting on. Conversations flagged by safety systems may still be used for trust and safety work.

Team, Enterprise and API use are covered by Anthropic's commercial terms instead of these consumer rules. As with any chatbot, do not paste passwords, ID numbers or confidential client data. See our AI privacy and safety guide for simple habits.

How Claude compares

Claude and ChatGPT are close rivals: ChatGPT offers more built-in extras such as image generation and a larger app ecosystem, while Claude is often preferred for long documents, writing quality and agent-style coding. Gemini is the stronger pick if you rely on Google's apps or work with audio and video. Open-weight families such as Llama, Qwen and Mistral suit people who need to host a model themselves. Read ChatGPT vs Claude and Claude vs Gemini for side-by-side details.

FAQ

Is Claude free to use?

Yes, there is a free plan with usage limits. Paid plans add more usage, more models and features such as Claude Code and Research.

Who owns Claude?

Claude is developed by Anthropic, an independent AI company. Large tech firms have invested in Anthropic, but Claude is Anthropic's own product.

Is Claude open source?

No. Claude's model weights are not published, so you can only use Claude through Anthropic's apps, its API, or cloud platforms that offer it.

Can Claude search the web?

Yes. Claude can search the web and cite sources in its answers. Paid plans also include a deeper Research mode for longer investigations.

Is ChatG connected to Claude or Anthropic?

No. ChatG is an independent AI chat website and is not affiliated with Anthropic. This page is an informational guide. If you want a free browser chat with no sign-up, you can try ChatG free.