AI Assistant / LLM

Claude

Anthropic's AI assistant — built for safe, nuanced work

Claude is Anthropic's flagship AI assistant, available at claude.ai and via API. Known for long context windows, careful reasoning, low hallucination rates, and a tone that feels less robotic than alternatives. The Claude 3.x and 4.x model families are the backbone of thousands of production AI applications.

What Claude does

Claude is a general-purpose AI assistant that can write, reason, analyze, code, summarize, and converse. Its standout strengths are long document analysis (up to 200K tokens), careful instruction-following, nuanced writing, and reduced likelihood of confident-sounding hallucinations compared to peers.

Is it right for you?

Claude is best for…

Long document analysis and summarization (contracts, reports, research papers)
Writing that needs to sound like a human, not a robot
Complex reasoning and structured analysis tasks
Building AI applications via Anthropic API
Coding tasks, particularly with Claude Code or API integration
Sensitive domains where accuracy and careful hedging matter (legal, medical summaries)

Not the best choice if…

Real-time internet search (use Perplexity or ChatGPT with Browsing for this)
Image generation (Claude analyzes images but does not generate them)
Voice-first interactions (use ChatGPT voice mode)

Pricing

Free

Free tier at claude.ai with rate-limited Claude 3.5 Sonnet access

Paid

Claude Pro: $20/month for 5x more usage, Claude 3.7 Sonnet and Opus access

Enterprise

Claude for Work: team plans from $25/user/month with admin controls and higher limits

Key features

200K token context window

Feed Claude an entire book, codebase, or legal document and ask questions about it — it holds far more context than most alternatives.

Extended thinking

Claude 3.7 Sonnet and Claude 4 can "think" before responding — reasoning step-by-step through hard problems before committing to an answer.

Artifacts

Claude.ai surfaces interactive artifacts — code previews, live React components, and documents — in a side panel so you can iterate visually.

Projects

Projects let you give Claude persistent context (custom instructions + uploaded documents) that carry across conversations.

API with tool use

The Anthropic API supports function calling (tool use), streaming, vision, and prompt caching — making Claude the backbone of enterprise AI apps.

Safety and alignment

Built by Anthropic with Constitutional AI and RLHF-based alignment. Claude refuses harmful requests more consistently than most frontier models.

Real-world use cases

Analyze a 100-page contract in minutes

Paste or upload a legal document and ask Claude to identify key clauses, risks, obligations, and renewal terms — it handles the full document in one pass.

Write and edit polished long-form content

Claude produces first drafts of reports, proposals, and technical documentation that require minimal editing — its prose is notably less stilted than GPT-4.

Build an AI application via API

Use the Anthropic API to integrate Claude into your product. Tool use (function calling) lets Claude take actions in your system based on user input.

Code review and explanation

Paste code and ask Claude to review for bugs, security issues, or explain what it does — excellent for onboarding or auditing unfamiliar code.

Research synthesis

Feed Claude multiple papers, articles, or reports and ask for a synthesis, comparison, or structured summary with source attribution.

How to get started with Claude

Start at claude.ai

Create a free account at claude.ai. The free tier gives you access to Claude 3.5 Sonnet with daily usage limits.

Try a Project

Create a Project (left sidebar), add custom instructions describing your role and context, and upload reference documents. Claude will remember these across conversations.

Use clear, specific prompts

Claude responds well to prompts that specify the output format, audience, and constraints. "Write a 300-word executive summary of this report for a non-technical audience" outperforms "summarize this."

Upgrade for more power

Claude Pro ($20/month) unlocks Claude 3.7 Sonnet with extended thinking, 5x more usage, and file uploads.

Access via API for development

Get an Anthropic API key at console.anthropic.com. Start with claude-sonnet-4-6 for the best balance of speed, cost, and capability.

Pro tips

→For complex reasoning tasks, add "think step by step" or "use extended thinking" to trigger Claude's deliberative reasoning mode.
→Use Projects with uploaded documents to give Claude persistent knowledge about your company, product, or domain.
→When the output quality drops mid-conversation, start a fresh conversation — Claude's quality degrades as context fills up.
→For writing tasks, provide examples of your preferred style in the prompt. Claude imitates voice very accurately.
→Use prompt caching via the API to dramatically reduce costs when the same long system prompt is reused across many requests.

Frequently asked questions about Claude

What is the difference between Claude models (Haiku, Sonnet, Opus)?

Claude Haiku is the fastest and cheapest model, ideal for simple classification, summarization, and high-volume tasks. Claude Sonnet is the all-around best choice — strong reasoning, good speed, moderate cost. Claude Opus is the most capable for complex reasoning and difficult tasks, but slower and more expensive. For most applications, start with Sonnet.

How does Claude compare to ChatGPT?

Claude generally outperforms ChatGPT on long document analysis, instruction-following, and nuanced writing. ChatGPT has advantages in real-time web browsing, image generation (via DALL-E), and voice interaction. For coding, both are strong — Claude Code is a standout for agentic use cases. For most knowledge work and writing, Claude is considered the better choice as of 2025.

Can Claude browse the internet?

Claude does not browse the internet by default. Anthropic has introduced web search as a tool in some Claude interfaces, and the Anthropic API supports web search as a tool use capability. However, Claude's training data has a knowledge cutoff, so for real-time information (news, stock prices, live data) you need to provide that context or use a model with built-in browsing.

Is Claude safe to use for confidential work?

Anthropic offers enterprise/Teams plans with enhanced privacy controls. By default, claude.ai conversations are not used to train models on the paid plan. For the API, review Anthropic's data processing terms. Do not share genuinely classified or legally privileged information with any LLM service without reviewing the vendor's data handling terms and your organization's AI policy.

What is Claude for Work?

Claude for Work (formerly Claude Teams) is Anthropic's enterprise offering. It includes higher usage limits, admin console, SSO, a business agreement, and enhanced privacy. Pricing starts around $25/user/month. It is the right choice for companies deploying Claude to multiple team members who need guaranteed capacity and enterprise data handling.