Getting Started: Claude.ai and the API

Ready to start using Claude? This lesson walks you through every way to access it — from the free web interface to the developer API. By the end, you'll have Claude up and running.

Option 1: Claude.ai (The Easiest Way)

The simplest way to use Claude is through the web interface at claude.ai.

Creating Your Account

1. Go to claude.ai
2. Click Sign Up
3. Choose a sign-up method:
   • Google account — Fastest option, one click
   • Email address — Create a password and verify your email
   • Apple account — Available if you prefer Apple sign-in
4. Complete the brief onboarding

Free vs Pro vs Max

Claude offers several plans. Prices change from time to time, so check claude.com/pricing for the latest. At the time of writing:

Plan	Price	What You Get
Free	$0/month	Sonnet and Haiku, web search, file creation, memory, Artifacts, voice mode, up to 5 Projects
Pro	$20/month ($17/month billed yearly)	More usage, Opus, unlimited Projects, Research, Claude Code, Claude in Chrome
Max	From $100/month	5x or 20x the usage of Pro, the Fable model, priority access, and early access to new features
Team	$25 per seat/month ($20 billed yearly)	Shared workspace for companies, admin controls, single sign-on
Enterprise	Custom	Advanced security, compliance, and admin tools for large organizations

Start with Free. The free plan includes Claude Sonnet, which is excellent for most tasks, plus web search, file uploads, and Projects. Upgrade to Pro later if you hit the usage limits often or want Opus and Research.

Your First Conversation

Once you're signed in, you'll see a text input box. Here's how to have your first conversation:

Try this prompt:

I'm new to AI assistants. Can you explain what you can help me with,
and give me three specific examples of tasks I could try right now?

Claude will respond with practical suggestions tailored to a beginner. Notice how it structures its response clearly and avoids overwhelming you.

A few things to try next:

Summarize this article for me: [paste an article]

Help me write a professional email declining a meeting invitation

Explain how compound interest works like I'm 15 years old

Navigating the Interface

The Claude.ai interface is straightforward:

• New chat — Start a fresh conversation (top left)
• Chat history — Find previous conversations in the sidebar
• Model selector — Choose which Claude model to use (Opus needs Pro or higher, and Fable is included from Max up)
• File upload — Attach documents, images, or code files using the paperclip icon
• Artifacts panel — When Claude creates code or documents, they appear in a side panel

Option 2: Claude Mobile and Desktop Apps

Claude also has apps:

• iOS — Available on the App Store
• Android — Available on Google Play
• Windows and Mac — Download the desktop app from the Claude website

The apps sync with your claude.ai account, so your conversations carry over. They're great for:

• Quick questions while away from your computer
• Reading and discussing documents on your phone
• Voice mode, where you talk with Claude out loud and hear its answers

Option 3: The Anthropic API (For Developers)

If you're a developer or want to integrate Claude into applications, Anthropic offers an API.

Getting API Access

1. Go to console.anthropic.com
2. Create an account (separate from your claude.ai account)
3. Add a payment method — API access is pay-per-use
4. Generate an API key from the dashboard

API Pricing Basics

API pricing is based on tokens (roughly 1 token = 0.75 words). "Input" is the text you send, and "output" is the text Claude writes back. Prices for the current models at the time of writing:

Model	Input Price	Output Price
Claude Haiku 5.5	$0.10 / million tokens	$0.50 / million tokens
Claude Sonnet 5.5	$2 / million tokens	$10 / million tokens
Claude Opus 5.5	$4 / million tokens	$20 / million tokens
Claude Fable 5.1	$10 / million tokens	$50 / million tokens

Haiku's price is for prompts up to 100,000 tokens. Longer prompts cost more.

A 10-page document is about 7,000 tokens. Sending it to Sonnet costs one or two cents. Check Anthropic's pricing page for the latest prices before you build anything.

A Simple API Example

Here's what an API call looks like in Python:

import anthropic

# Reads your key from the ANTHROPIC_API_KEY environment variable,
# so it never sits in your code.
client = anthropic.Anthropic()

message = client.messages.create(
    model="claude-opus-5-5",  # or "claude-sonnet-5-5" for everyday tasks at half the price
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "What is the capital of France?"}
    ]
)

# A reply can contain several blocks. Print only the text.
for block in message.content:
    if block.type == "text":
        print(block.text)

Never paste your API key into your code or share it. Anyone who has it can use your account and run up your bill.

You don't need to learn the API to use Claude effectively — the web interface is perfectly capable for most users. The API is for building applications, automating workflows, or integrating Claude into your own tools.

Option 4: Third-Party Integrations

Claude is also available through various third-party platforms:

• Amazon Bedrock — Use Claude through AWS
• Google Cloud Vertex AI — Access Claude via Google Cloud
• Cursor, Windsurf, and other code editors — Claude powers AI features in development tools
• Slack — Claude can be added as a Slack bot for team use

Tips for Getting Started

Start Simple

Don't try to master everything at once. Begin with basic conversations and gradually explore features:

1. Week 1 — Ask questions, get help with writing
2. Week 2 — Try uploading documents for analysis
3. Week 3 — Explore Projects and custom instructions
4. Week 4 — Build workflows that combine multiple features

Write Naturally

You don't need special syntax or keywords. Talk to Claude like you'd talk to a knowledgeable colleague:

This works well:

I'm writing a quarterly report for my team. Can you help me
structure it? We had a good quarter with 15% revenue growth
but we missed our customer acquisition target.

You don't need:

SYSTEM: You are a business report writer. TASK: Generate
a quarterly report. PARAMETERS: revenue=15%, acquisition=missed

Simple, natural language gets excellent results from Claude.

Use the File Upload

One of Claude's most practical features is file upload. You can attach:

• PDFs and documents
• Images and screenshots
• Code files
• Spreadsheets (CSV)
• Text files

Simply click the paperclip icon and select your file. Claude will read it and you can ask questions about it.

Key Takeaways

• The easiest way to start is at claude.ai — sign up for free in under a minute
• The free plan gives you Claude Sonnet, web search, file uploads, voice mode, and up to 5 Projects
• Claude Pro ($20/month at the time of writing) adds more usage, Opus, unlimited Projects, and Research
• Apps are available on iOS, Android, Windows, and Mac
• The API is pay-per-use for developers building applications
• Write naturally — Claude responds best to clear, conversational prompts
• Start simple and explore new features gradually over time