How to Use Claude

The 50-page report that changed everything

Deepa is a strategy consultant. A client just sent her a 50-page market analysis PDF and needs a one-page executive summary by tomorrow morning. She pastes the document into ChatGPT — but it chokes. The free tier can only handle a portion of the text. She tries splitting it into chunks, feeding them in one at a time. Forty minutes later, she has five disconnected summaries that contradict each other.

Her colleague Raj leans over: "Try Claude."

Deepa uploads the entire 50-page PDF to Claude in one go. She types: "Summarize this market analysis into a one-page executive brief with 5 key findings, 3 risks, and 2 recommendations. Use bullet points. Audience: C-suite executives who haven't read the full report."

Ninety seconds later, she has a coherent, well-structured summary that captures the document's actual argument — not just keyword extraction, but the reasoning behind the conclusions. She edits two bullets, adds a client-specific note, and sends it. Total time: 8 minutes.

Same task. Different tool. Raj wasn't smarter. He just knew which AI to reach for when the document was long and the thinking needed to be careful.

What Claude actually is

Claude is an AI assistant built by Anthropic, a San Francisco-based AI safety company founded in 2021 by Dario Amodei (CEO), Daniela Amodei (President), and other former OpenAI researchers. Where OpenAI prioritized rapid consumer adoption with ChatGPT, Anthropic focused on building an AI that is helpful, harmless, and honest.

That difference in philosophy shows up in how Claude behaves. It tends to be more measured in its responses, more willing to say "I'm not sure," and less likely to confidently make things up. For many professional use cases — legal analysis, financial research, technical writing — that carefulness is exactly what you want.

Claude vs. ChatGPT: honest comparison

This is the question everyone asks, so let's address it head-on. Neither tool is universally "better" — they have different strengths.

The bottom line: Use ChatGPT when you need quick creative output, image generation, or web browsing. Use Claude when you need careful reasoning, long document processing, or precise instruction-following.

Claude's key features

1. The 200K context window

This is Claude's signature advantage. A "context window" is how much text the AI can hold in its working memory during a single conversation. At 200K tokens, Claude can process roughly 150,000 words — that's a 500-page book in a single conversation.

What this means in practice:

• Upload an entire legal contract and ask specific questions about clauses
• Paste a full codebase and ask for a refactoring plan
• Feed in 20 customer interview transcripts and ask for theme analysis
• Compare two 30-page documents side by side

2. Artifacts

When Claude generates code, documents, SVGs, or other structured content, it can render them in a live preview panel called "Artifacts." You can see a React component actually running, edit a document in real time, or view a generated diagram — without leaving the conversation.

3. Projects

Projects let you upload reference files (company docs, style guides, product specs) that persist across conversations. Instead of re-uploading your brand guidelines every time, you set them once in a project and every new conversation in that project has access to them.

4. Vision

Claude can read and analyze images. Upload a screenshot of a dashboard, a photo of a whiteboard, a chart from a report, or a UI mockup — and ask questions about it. Useful for design feedback, data interpretation, and debugging visual layouts.

5. System prompts (custom instructions)

You can set persistent instructions that shape how Claude responds in every conversation. This is where you tell Claude your role, your preferences, and your constraints once — so you don't have to repeat them.

Best use cases for Claude

Based on its strengths, here's where Claude genuinely outperforms other tools:

Long document analysis — Summarizing reports, extracting key points from contracts, comparing documents, analyzing research papers. The 200K context window means you don't need to split documents into chunks.

Coding and technical work — Claude Sonnet is particularly strong at code generation, debugging, and explaining complex code. It follows technical specifications carefully and produces clean, well-structured code.

Careful reasoning tasks — Financial analysis, legal review, risk assessment — any task where you'd rather the AI say "I'm not sure about this part" than confidently give you wrong information.

Structured writing — Blog posts, reports, documentation, email sequences. Claude is good at following detailed formatting instructions and maintaining consistent tone across long pieces.

Data analysis and synthesis — Paste in raw data (CSV, JSON, or just tables) and ask Claude to find patterns, create summaries, or generate charts via Artifacts.

Prompting techniques that work especially well with Claude

Claude responds to a few techniques better than most other AI tools. These aren't generic "prompt tips" — they are specific to how Claude processes instructions.

1. Use XML tags to structure your prompt

Claude was specifically trained to understand XML-style tags as organizational markers. This helps it parse complex prompts with multiple sections.

<role>You are a senior financial analyst.</role>

<context>
I'm preparing a board presentation on Q3 results.
Revenue was $4.2M (up 12% YoY). Costs rose 18%.
</context>

<task>
Write 3 slides worth of speaker notes covering:
1. Revenue highlights
2. Cost concerns
3. Recommended actions for Q4
</task>

<format>
- Each slide: title + 4-5 bullet points
- Tone: confident but honest about cost issues
- No jargon the board wouldn't understand
</format>

2. Ask Claude to think step by step

When a task requires reasoning (math, logic, analysis), explicitly ask Claude to show its work. It produces more accurate results when it "thinks out loud."

Analyze whether we should expand into the European market.
Think through this step by step:
1. What are the potential benefits?
2. What are the risks?
3. What data would we need to make this decision?
4. Based on general patterns, what's your recommendation?

3. Give Claude a role with constraints

Claude follows role assignments faithfully. The more specific your role description and constraints, the more tailored the output.

You are a copy editor at The Economist. Edit the following
article for clarity, conciseness, and factual accuracy.
Flag anything that seems unsubstantiated. Do NOT add
marketing language. Do NOT use exclamation marks.
Keep sentences under 25 words where possible.

4. Use examples to set the pattern

If you want output in a specific format, show Claude one example and it will follow the pattern precisely.

Write product descriptions for these items in this format:

Example:
Product: Wireless Noise-Canceling Headphones
One-liner: Block out the world. Keep the music.
Description: 30-hour battery life, adaptive noise
canceling, and memory-foam ear cushions that make
6-hour flights feel like 6 minutes.

Now do the same for:
- Standing desk converter
- Ergonomic keyboard
- USB-C hub

Claude for different roles

Claude adapts to many professional contexts. Here's how different roles get the most from it:

What Claude can't do

Being clear about limitations saves you time and frustration:

• No internet access by default — Claude works from training data; web search is available on some plans (check claude.ai for current features). You must paste relevant content into the conversation.
• No image generation in some plans — check claude.ai for Claude's current image capabilities, as these have evolved. It can analyze images you upload.
• No persistent memory across conversations — Each new conversation starts fresh (unless you're using Projects with uploaded reference files). Claude doesn't remember what you discussed last Tuesday.
• Knowledge cutoff — Claude's training data has a cutoff date. It won't know about events that happened after that date unless you provide the information.
• Not a database — Claude can analyze data you give it, but it's not connected to your databases, CRMs, or analytics tools. You need to export and paste or upload the data.
• Can be wrong — Claude reduces confident hallucination compared to some tools, but it still makes mistakes. Never use AI output in high-stakes contexts (legal filings, medical decisions, financial reports) without human review.

Getting started: free tier vs. Pro

Here's the practical breakdown for deciding which plan you need:

Start free. Use Claude for a week. If you find yourself hitting usage limits or wanting the Opus model for harder tasks, upgrade. The Pro plan pays for itself if Claude saves you even 30 minutes per week.

To get started right now:

1. Go to claude.ai
2. Create an account (email or Google sign-in)
3. Start a conversation with a real task — not "hello," but something you actually need done today
4. Upload a document if you have one — that's where Claude shines

Key takeaways

• Claude is built by Anthropic, a separate company from OpenAI. Its focus on safety means it tends to be more careful and less prone to confident hallucination.
• The 200K context window is Claude's biggest practical advantage. If your task involves long documents, choose Claude.
• Claude excels at careful reasoning, structured output, and following complex instructions. Use ChatGPT for quick creative tasks and image generation; use Claude for analysis and precision.
• XML tags, role assignments, and step-by-step instructions work especially well with Claude because of how it was trained.
• Start with the free tier. Upgrade to Pro only when you're using Claude daily and hitting limits.
• Always verify important facts. Claude is a drafting and reasoning partner, not an oracle.