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Which Claude Should I Use?

Beginner

"Claude" comes in a few flavors. Pick by what you're trying to do, not by which you've heard of.

What you'll learn
  • Match your goal to the right Claude surface: chat, Claude Code, or the API
  • Know when mobile and voice fit into the picture
  • Understand how the three surfaces work together as you level up
  • Get a quick read on which model to reach for once you start building

The 30-second decision​

The three surfaces at a glance​

SurfaceBest forWhoStart here
Claude.aiWriting, research, analysis, learning, planning, everyday questionsEveryone, no setupGetting Started with Claude.ai
Claude CodeWorking in a codebase — reading, editing, running commands, fixing testsDevelopers (and the technically curious)What Claude Code Is
API & Agent SDKApps, automations, and agents that call Claude programmaticallyDevelopers shipping a product or pipelineYour First API Call

Claude.ai — the chat apps​

Claude.ai is the no-setup starting point for everyone. You also get it on mobile (iOS/Android) and by voice — great for capturing ideas on the go. Power it up with Projects, custom instructions, and Artifacts.

Claude Code — the agentic coding tool​

Claude Code works inside your project. It reads, edits, runs commands, and fixes tests — acting on your files with your permission.

The API & Agent SDK — build Claude into your own software​

The API and Agent SDK let your own software call Claude programmatically, so you can ship AI features, automations, and agents.

They work together​

These aren't rival products — most people graduate across them:

You want to…Use
Draft an email, summarize a PDF, brainstormClaude.ai (or voice/mobile)
Refactor a module, add tests, fix a bugClaude Code
Add an AI feature to your appThe API / Agent SDK
Not sure? Start with chat

Claude.ai needs zero setup and teaches you how Claude "thinks." The skills transfer everywhere else.

Which model, once you're building?​

Picking a surface is step one. When you move to Claude Code or the API, you also pick a model — Haiku, Sonnet, or Opus. Answer three quick questions and this picker suggests a starting point:

Model picker
Task difficulty
What matters most
Request volume
Recommended
Claude Sonnet

The balanced default — strong reasoning and coding at a fraction of Opus cost. Start here, and only move up if you hit a real quality ceiling.

Look up the exact model ID on the models table. Rule of thumb only — run a quick eval on your own inputs to be sure.

Don't hard-code the names

Model lineups and prices change. Always confirm the current model IDs on the Choosing a Claude Model page before you ship.

Check yourself​

Check yourself

0/3
  1. You want to draft an email and summarize a PDF — no setup. Which surface?
  2. You need to refactor a module and fix failing tests inside a real project. Which surface?
  3. Where should you confirm the current model names and prices?
Key takeaways
  • Claude.ai: zero-setup chat for writing, research, and everyday work — also on mobile and by voice
  • Claude Code: an agent that acts inside your codebase
  • API & Agent SDK: build Claude into your own software
  • They compose — most people start with chat and graduate to Code and the API
  • Pick a model (Haiku / Sonnet / Opus) only once you're building, and verify current IDs before shipping

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