How to Use Claude 4.5: The Complete Guide

If ChatGPT is the household name in AI assistants, Claude is the quiet overachiever that developers and power users swear by.

Anthropic's Claude 4.5 family—Opus, Sonnet, and Haiku—represents some of the most capable AI models available today. They're particularly strong at coding, long-form reasoning, and agentic tasks where the AI operates autonomously.

This guide covers everything: from creating your account to advanced prompting techniques that unlock Claude's full potential.

Why Claude 4.5?

Before we dive in, here's what makes Claude different:

• Exceptional coding abilities: Claude excels at writing, debugging, and explaining code
• Long context window: Handle massive documents without losing the thread
• Agentic autonomy: Claude can run complex, multi-step tasks with minimal guidance
• Computer use: Claude can operate your desktop (browse, click, type)
• Thoughtful, nuanced responses: Less "salesy," more genuine engagement
• Strong safety alignment: Designed to be helpful, harmless, and honest

If ChatGPT feels like a confident extrovert, Claude feels like a thoughtful friend who happens to be brilliant.

The Claude 4.5 Family

Anthropic offers three model tiers:

My recommendation: Start with Sonnet 4.5—it's the best balance of capability and cost. Use Opus for truly complex tasks, Haiku for quick queries.

Getting Started

Step 1: Create Your Account

1. Go to claude.ai
2. Sign up with Google, email, or SSO
3. Choose your plan:
   • Free: Limited messages, access to Claude Sonnet
   • Pro ($20/month): 5x more usage, priority access, Opus 4.5
   • Max ($40/month): Even higher limits, early features

Step 2: Understand the Interface

When you log in, you'll see:

• Chat area: Your conversation with Claude
• New chat: Start fresh conversations
• Projects: Organize related conversations (Pro feature)
• Artifacts: View/edit code, documents, or visualizations Claude creates

Step 3: Your First Conversation

Just start talking! Claude doesn't require special commands.

Try:

"Explain quantum computing to me like I'm a high school student."

Claude will respond thoughtfully and ask clarifying questions if needed.

How to Prompt Claude Effectively

Claude responds well to conversational, clear prompts. Here's how to get the best results:

Be Specific About What You Want

❌ "Write code" ✅ "Write a Python function that takes a list of numbers and returns only the prime numbers. Include docstrings and type hints."

Provide Context

Claude performs better with background:

"I'm building a SaaS dashboard for project management. The backend is FastAPI, frontend is React. I need help designing the API endpoints for task management."

Use Role Assignment

Give Claude a perspective:

"You are a senior software architect reviewing my code. Point out design flaws, security issues, and suggest improvements."

Break Down Complex Tasks

Instead of:

"Build me a website"

Try:

"I'm building a portfolio website. Let's start with: 1) What sections should I include? 2) What's the best tech stack for a simple, fast site?"

Ask for Multiple Options

"Give me 3 different approaches to solve this problem, with pros and cons of each."

Request Specific Formats

"Explain this in a numbered list with clear headers." "Create a markdown table comparing X, Y, Z." "Write the code, then explain what each section does."

Claude's Standout Features

1. Artifacts (Interactive Content)

When Claude generates code, documents, or visualizations, they appear as "Artifacts"—interactive panels you can view, edit, and export.

Try:

"Create a React component for a pricing table with three tiers."

The component appears as an artifact you can copy, modify, or preview.

2. Projects (Organized Workspaces)

Pro users can create Projects with:

• Custom instructions (system prompts)
• Uploaded reference files
• Persistent context across conversations

Example: Create a "React Development" project with:

• Custom instruction: "I'm building a React app with TypeScript, Tailwind CSS, and React Query. Follow these conventions..."
• Uploaded files: Your codebase, docs, style guide

Every conversation in that project inherits the context.

3. Code Execution

Claude can run code directly in the conversation:

"Run this Python code and show me the output:

import random
print([random.randint(1, 100) for _ in range(10)])
```"

Claude executes it and shows results.

4. File Handling

Upload files directly:

• PDFs, documents, spreadsheets
• Images for analysis
• Code files for review

[Upload contract.pdf] "Summarize the key terms and identify any unusual clauses."

5. Computer Use (Beta)

Claude can operate your computer:

• Browse websites
• Click buttons and fill forms
• Take screenshots and read the screen

This requires the API and special setup, but enables powerful automation.

Claude for Coding

Coding is where Claude truly shines. Here's how to maximize it:

Write New Code

"Write a Node.js Express API with the following endpoints:

• POST /users (create user with email, password)
• GET /users/:id (get user by ID)
• PUT /users/:id (update user) Use TypeScript, Prisma for the database, and include input validation."

Claude will generate comprehensive, production-ready code.

Debug Existing Code

"I'm getting this error: [paste error]

Here's my code: [paste code]

What's wrong and how do I fix it?"

Claude identifies the issue and provides the fix.

Explain Code

"Explain this code line by line. Assume I'm an intermediate developer:

[paste confusing code]"

Refactor and Improve

"Review this function for:

1. Performance issues
2. Security vulnerabilities
3. Code quality
4. Suggest improvements

[paste code]"

Learn New Technologies

"I know Python but want to learn Go. Teach me Go by rewriting this Python code in Go and explaining the differences:

[paste Python code]"

Claude for Writing

Claude excels at nuanced, well-structured writing:

Long-Form Content

"Write a 2,000-word blog post about the future of remote work. Include statistics, multiple perspectives, and actionable advice for both employers and employees. Use an engaging, conversational tone."

Editing and Improvement

"Edit this for clarity, concision, and impact. Maintain my voice but make it stronger:

[paste draft]"

Research and Analysis

"Research the pros and cons of microservices architecture vs monolithic architecture. Include when to use each, real-world examples, and potential pitfalls."

Different Voices

"Rewrite this product description in three different tones:

1. Professional and corporate
2. Casual and friendly
3. Luxury and premium

[paste description]"

Claude for Research

Claude can process and synthesize massive amounts of information:

Document Analysis

[Upload research paper PDF] "Summarize this paper's key findings, methodology, limitations, and practical implications."

Multi-Document Comparison

[Upload multiple files] "Compare these three articles on the same topic. Where do they agree? Where do they contradict each other?"

Information Synthesis

"I'm researching [topic]. Based on what you know:

1. What are the key debates in this field?
2. Who are the major thinkers/researchers?
3. What are the emerging trends?
4. What does the evidence suggest?"

Advanced Techniques

Chain of Thought Prompting

Ask Claude to reason step-by-step:

"Think through this problem step by step before giving your final answer:

[complex question]"

Structured Output

Request specific formats:

"Provide your analysis in this exact JSON format:

{
  \"summary\": \"...\",
  \"pros\": [...],
  \"cons\": [...],
  \"recommendation\": \"...\"
}
```"

Iterative Refinement

Don't accept the first response—iterate:

"Good start. Now make it more concise." "Add more technical depth to section 3." "Rewrite the introduction to be more engaging."

Context Priming

Set the stage at the start of complex tasks:

"I'm going to share a large codebase with you. Your job is to:

1. Understand the overall architecture
2. Identify potential issues
3. Suggest improvements

Before I share the code, confirm you understand the task and ask any clarifying questions."

Claude vs. ChatGPT

My take: Use Claude for coding, research, and technical writing. Use ChatGPT for creative projects and when you need specific plugins/integrations.

Pricing Deep Dive

For developers using the API:

• Haiku 4.5: $1/$5 per million tokens (input/output)
• Sonnet 4.5: $3/$15 per million tokens
• Opus 4.5: $5/$25 per million tokens

Tips for Daily Use

1. Use Projects: Organize by topic/project for persistent context
2. Upload files liberally: Claude handles them well
3. Save good conversations: Export useful threads
4. Iterate don't restart: Refine responses rather than starting over
5. Be conversational: Claude responds well to natural language
6. Use Haiku for quick queries: Switch models based on task complexity
7. Enable memory (when available): Let Claude remember across sessions

The Bottom Line

Claude 4.5 isn't just another chatbot—it's a sophisticated thinking partner that excels at complex reasoning, coding, and nuanced communication.

The key to unlocking its potential is treating it like a brilliant collaborator: provide context, be specific about what you need, and iterate on responses.

Whether you're debugging code, researching a complex topic, or drafting an important document, Claude 4.5 is one of the most capable AI assistants available today.

Go give it a try.

Related articles:

• ChatGPT vs Claude vs Gemini: Which Should You Use?
• AI Coding Assistants: What Actually Works
• 50 ChatGPT Prompts That Actually Work