What is Claude?
Claude is Anthropic's AI assistant, designed with a focus on being helpful, harmless, and honest. While it launched after ChatGPT, Claude has earned a strong reputation for thoughtful responses, excellent writing, and the ability to work with very long documents.
Current Models
As of mid-2026, Claude offers a family of Claude 4 models, each optimized for different needs. They follow the same three-tier structure Anthropic has used for years: Opus (most capable), Sonnet (balanced), and Haiku (fastest).
Claude Sonnet 4.6
Sonnet 4.6 is Anthropic's balanced model for everyday use, offering a strong combination of intelligence, speed, and cost. For most people, it's the best starting point.
| Feature | Details |
|---|---|
| Intelligence | Strong reasoning for general tasks |
| Speed | Fast response times |
| Context | 1M tokens (~750,000 words) |
| Vision | Can analyze images and documents |
| Best for | Most tasks—writing, coding, analysis |
Claude Opus 4.7
Opus 4.7 is Anthropic's most capable model, designed for the most complex tasks—deep reasoning and agentic coding in particular.
| Feature | Details |
|---|---|
| Intelligence | Highest reasoning capability |
| Speed | Slower than Sonnet |
| Context | 1M tokens |
| Best for | Complex analysis, research, agentic coding, nuanced writing |
Claude Haiku 4.5
The fastest and most affordable Claude model, ideal for quick tasks and high-volume applications.
| Feature | Details |
|---|---|
| Speed | Fastest in the Claude family |
| Context | 200K tokens |
| Cost | Most affordable |
| Best for | Quick questions, simple tasks, chatbots |
Key Features
Massive Context Window
Claude's standout feature is its very large context window—up to 1M tokens on Opus 4.7 and Sonnet 4.6 (Haiku 4.5 is 200K):
- Process entire books - Upload and analyze full novels or textbooks
- Review long codebases - Analyze thousands of lines of code at once
- Compare multiple documents - Upload several PDFs and compare them
- Maintain conversation context - Long conversations don't lose earlier information
For comparison, a 1M-token context window can hold roughly:
- ~750,000 words of text
- Several full-length books at once
- Hours of meeting transcripts
- Large codebases with many files
Projects
Claude's Projects feature lets you organize related conversations and documents:
- Upload knowledge files - PDFs, code, documents the project can reference
- Set project instructions - Define context and preferences that persist
- Organized workspace - Keep related work together
- Team collaboration - Share projects with team members (on Team plans)
Artifacts
When Claude creates code, documents, or other substantial content, it can display them as Artifacts:
- Interactive previews - See rendered HTML, React components, or visualizations
- Easy editing - Request changes and see updates in real-time
- Export options - Download or copy generated content
- Version history - Compare different iterations
Web Search
Claude can search the web for current information, with inline citations so you can verify sources. Web search is available on all plans, including the free tier.
Voice Mode
Claude's mobile app offers voice conversations, with several voice options to choose from. This makes hands-free, conversational use possible just like a phone call.
Code Execution and Data Analysis
Beyond writing and explaining code, Claude can run code to analyze data, work through calculations, and produce results and charts—not just show you a snippet. You can upload files (such as a CSV) and ask Claude to process them.
Computer Use
Claude can also interact with computer interfaces directly—navigating websites, filling out forms, clicking buttons and menus, and taking screenshots to analyze them. Originally a research beta, this now powers agentic workflows where Claude completes multi-step tasks on your behalf.
What Claude Does Well
Claude has distinct strengths:
Long Document Analysis
- Summarizing lengthy reports
- Extracting information from books
- Comparing multiple documents
- Finding specific details in large files
Nuanced Writing
- Matching specific tones and styles
- Thoughtful, well-structured prose
- Academic and professional writing
- Avoiding generic AI-sounding text
Careful Reasoning
- Breaking down complex problems
- Acknowledging uncertainty appropriately
- Considering multiple perspectives
- Avoiding overconfident conclusions
Code Quality
- Clean, well-documented code
- Thoughtful architecture decisions
- Good at explaining reasoning
- Strong at code review and refactoring
Ethical Considerations
- Handles sensitive topics thoughtfully
- Less likely to produce harmful content
- Transparent about limitations
- Balances helpfulness with safety
Limitations to Know
Claude has limitations too:
- No native image generation - Claude can analyze images but cannot create them (unlike ChatGPT's built-in image generation)
- Smaller ecosystem - Fewer third-party integrations and a smaller marketplace of community-built assistants than ChatGPT
- Sometimes too cautious - May refuse requests that are actually harmless
- Can still be wrong - Like any AI, Claude can state incorrect information confidently, so verify important facts
Key Takeaways
- Claude offers three models: Sonnet 4.6 for daily use, Opus 4.7 for complex tasks, Haiku 4.5 for speed
- A very large context window (up to 1M tokens on Opus 4.7 and Sonnet 4.6) handles entire books and large codebases
- Web search, voice mode, code execution, Projects, and Artifacts are all available
- Excels at long document analysis, nuanced writing, and careful reasoning
- Smaller ecosystem than ChatGPT, and no native image generation