Introduction to Claude Chat
Claude Chat is the main conversation window at claude.ai. You send messages, Claude replies in a thread, and you follow up — for writing, file questions, code help, and similar tasks.
What Claude Chat is
Claude Chat is the conversation interface: you send messages and Claude replies in a thread. It runs on the web at claude.ai, in the Claude Desktop app, and on mobile (iOS and Android).
Claude Code works in your terminal on project files. Cowork runs tasks on your desktop. Chat is the standard interface for short questions and longer threads.
The chat interface
Three main areas: a sidebar listing past conversations, a model selector at the top, and the chat area where messages appear.
A list comprehension builds a new list from an existing one in a single line:
for n in range(5): squares.append(n ** 2)
Format: [expression for item in iterable]
What you can do in chat
Attach files, paste text, or describe what you need:
Write and edit
Drafts, emails, essays, scripts, reports — any format.
Code
Write, explain, debug, or refactor code in any language.
Summarize
Condense long documents or meeting notes into key points.
Analyze images
Describe photos, charts, or screenshots you upload.
Search the web
Get up-to-date answers when web search is enabled.
Extended thinking
Deeper reasoning for maths, logic, or multi-step problems.
Translate
Work across languages or explain phrasing nuances.
Brainstorm
Generate ideas, compare options, or test arguments.
Starting a useful conversation
Specific prompts produce better results. Compare these two approaches for the same task:
| Approach | Prompt | Why it matters |
|---|---|---|
| Vague | “Help me with my email.” | Claude must guess the audience, purpose, and tone. |
| Specific | “Write a short, polite follow-up email to a client who hasn't replied to my project proposal in a week. Keep it under 100 words.” | Format, recipient, context, tone, and length are all defined. |
- Give context — who you are, what the output is for, and who will read it.
- Set the format — bullet list, word limit, JSON, or another structure.
- Refine in follow-ups — ask for shorter text, a formal tone, or a new section.
- Attach files — upload a PDF, image, CSV, or code file and ask Claude to work with it directly.
Organising with Projects
Projects (Pro and above) group related conversations under one name. Each project can have a system prompt that applies to every chat, plus uploaded files Claude references automatically.
Choosing a model
Switch models any time using the selector at the top of the chat.
| Model | Speed | Best for |
|---|---|---|
| Haiku | Fastest | Quick questions, simple tasks, fast lookups |
| Sonnet | Balanced | Writing, analysis, coding, general questions |
| Opus | Deliberate | Complex analysis, long research, multi-step projects |
Chat, Cowork, or Claude Code
Anthropic ships three main tools for different jobs:
| You want to… | Chat | Cowork | Claude Code |
|---|---|---|---|
| Ask questions | Yes | — | — |
| Write or analyse | Yes | Yes — runs steps automatically | Yes — with files |
| Edit local files | — | Yes — full file access | Yes — in repo |
| Run multi-step tasks | — | Yes — automated steps | Yes — code tasks |
| Build software | Pair programming (manual) | — | Primary use case |
| Works on | Web, mobile, desktop | Claude Desktop | Terminal / IDE |
Before you continue
- Claude Chat runs on web, desktop, and mobile — free to start at claude.ai.
- Be specific about audience, format, and length; refine with follow-up messages.
- Projects (Pro+) group chats with shared files and a system prompt.
- Default to Sonnet; switch to Haiku for speed or Opus for depth.
- For local file edits or command execution, use Cowork or Claude Code instead.
What's Next
Core Capabilities — writing, summaries, research, brainstorming, maths, code help, and translation, with short examples.