Claude, by Anthropic

What is Claude?

Claude is an AI assistant made by Anthropic, a safety-focused AI company founded in 2021 by former OpenAI researchers. Unlike some AI tools that chase the flashiest demos, Anthropic built Claude with a deliberate philosophy: make an AI that is honest about what it doesn't know, careful with sensitive topics, and genuinely useful for serious work.

The result is an AI that feels less like a parlour trick and more like a thoughtful colleague. Claude excels at reading and synthesising long documents, writing in a natural voice, and following complicated instructions without losing the thread.

Anthropic's core research focus is "constitutional AI" — a method of training AI systems to be helpful, harmless, and honest by design. That philosophy shows up in how Claude behaves: it pushes back on requests it finds problematic, acknowledges uncertainty, and avoids the kind of sycophantic agreement that makes other AI tools feel hollow.

Claude models

Claude comes in three tiers, each suited to different tasks and budgets:

The short version: Sonnet is what most people use day-to-day. Opus is for when you need the absolute best answer and don't mind waiting a few extra seconds. Haiku is for developers building apps that need fast, cheap responses at scale.

Free vs Pro

Who should pay? If you hit your daily limit more than once a week, Pro is worth it. If you use Claude occasionally for writing or research, the free tier is genuinely good.

The magic moment

Here is the single most impressive thing Claude can do that most people don't know about.

Upload a 50-page contract — or an annual report, a grant proposal, a research paper — and ask:

I've uploaded a 50-page supplier contract. Please:
1. Summarise the key terms in plain English (5 bullet points)
2. Flag any clauses that seem risky or unusual for a standard agreement
3. List the 3 most important action items before signing
4. Note any deadlines or time-sensitive obligations

Claude will read the entire document and return a structured, useful answer in under 30 seconds. Claude handles a context window of up to 200,000 tokens — roughly 150,000 words, or about 500 pages — without losing track.

This alone is why lawyers, consultants, researchers, and business owners reach for Claude over other tools when serious document work is involved.

Step-by-step setup

1. Go to claude.ai
2. Click "Sign up" — use Google, Apple, or an email address
3. Verify your email if prompted
4. You land on the chat interface — type your first message or upload a file
5. To upload a file: click the paperclip icon in the message box and select your document
6. To start a Project: click "Projects" in the left sidebar → "New Project" — add instructions and files that persist across all conversations
7. On mobile: download the Claude app (iOS or Android) for voice mode

Total time: under 2 minutes.

Key features

Projects

Projects are Claude's version of a persistent workspace. You create a project, give it custom instructions, upload relevant documents, and every conversation inside it remembers the context automatically.

Example system prompt for a marketing project:

You are a marketing copywriter for Meridian Financial, a UK-based fintech startup.

Always write in British English.
Our tone is: confident but not arrogant, plain-English, no jargon, warm.
Target audience: small business owners aged 35–55.
Always end emails with a single clear call to action.
Never use the words "leverage" or "synergy".

With this in place, every message inside the project inherits these instructions — you never have to repeat yourself.

Artifacts

When Claude generates code, an HTML page, an SVG diagram, or a React component, it displays it as a live Artifact — an interactive preview pane next to the chat. Ask Claude to "build a simple tip calculator in HTML" and you get a working calculator you can immediately interact with.

File uploads

Claude accepts PDFs, Word documents (.docx), plain text, images (JPG, PNG, WebP), and CSV files. Upload multiple files in a single conversation to compare contracts side-by-side, analyse spreadsheets, or share screenshots of errors.

Voice mode

On the Claude mobile app, tap the microphone icon to have a spoken conversation with Claude. Useful for brainstorming on a walk, dictating ideas, or when typing is inconvenient.

How to get better results

Most people use AI like a search engine — short, vague queries — and get mediocre results. Claude rewards specificity and context.

1. Give Claude a role

Instead of: Write a cover letter

Try: You are an experienced HR consultant. Write a cover letter for a senior product manager role at a Series B SaaS startup. The candidate has 8 years of experience and is moving from enterprise to startup for the first time.

2. Specify the format you want

Instead of: Summarise this report

Try: Summarise this report in exactly 5 bullet points, each under 20 words. Then add a single sentence: the one thing I should act on immediately.

3. Tell Claude what NOT to do

Write a LinkedIn post about our product launch.
Do NOT use: innovative, game-changer, excited, thrilled.
Do NOT use exclamation marks.
Keep it under 150 words.

4. Ask for multiple options

Instead of: Write a subject line for this email

Try: Give me 5 different subject lines. Label them: Curiosity, Urgency, Benefit, Question, Provocative.

5. Iterate, don't restart

Claude remembers the whole conversation. If the first answer isn't right, reply: "That's close, but make it shorter and more direct" — don't start a new chat.

Real-world use by profession

Lawyers & legal professionals

Claude can read an entire contract without truncating it. Use it to flag non-standard clauses, summarise terms for clients in plain English, or draft first-pass NDAs for human review.

Read this employment contract. Highlight any clauses that deviate from standard UK
employment law. Flag anything that could disadvantage the employee. Use plain English —
the person reading this is not a lawyer.

Writers & content creators

Claude writes in a natural, non-robotic voice and takes style direction well. Use it for first drafts, editing passes, repurposing content across formats, or outlining.

Here's my rough draft: [paste draft]. Edit for clarity and warmth. Keep my voice —
don't make it sound polished or corporate. Flag any sentences that are unclear or too long.

Business owners

From drafting proposals to analysing customer feedback to preparing board summaries, Claude handles the writing and thinking work that eats up a small business owner's day.

Here are 47 customer reviews from the last quarter: [paste reviews].
Identify the top 3 recurring complaints and the top 3 most praised features.
Then suggest one concrete improvement we could make in the next 30 days.

Researchers & academics

Claude reads dense academic papers, synthesises literature across multiple documents, and helps structure arguments without producing flat, generic prose.

Here are three research papers on cognitive load theory. Identify where the authors agree,
where they contradict each other, and what questions remain unanswered.
Format as a comparison table, then a 3-paragraph synthesis.

HR professionals

Claude helps draft job descriptions, performance review frameworks, employee communications, and policy documents — including sensitive situations like redundancy notices.

Draft a redundancy consultation letter for a mid-level marketing manager.
UK employment law applies. Tone should be respectful and human.
Include: reason for redundancy, consultation timeline, next steps, who to contact.

Doctors & healthcare professionals

Claude is not a substitute for clinical judgement, but excellent for administrative writing: patient letters, referral summaries, and explaining complex conditions in plain language.

Write a patient-facing explanation of Type 2 diabetes management for someone newly diagnosed.
No jargon, Year 8 reading age. Cover: diet basics, exercise, medication overview, home monitoring.
Under 400 words.

Important: Claude should not be used to make clinical decisions or replace professional medical advice.

Prompt templates

Document summary

Read the attached document. Give me:
1. A one-paragraph plain-English summary (under 100 words)
2. The 5 most important facts or findings
3. Any action items or decisions that need to be made
4. One question I should be asking that this document raises but doesn't answer

Email draft

Write an email from [Your name/role] to [Recipient/role].
Purpose: [e.g., follow up after a meeting / request a deadline extension]
Tone: [e.g., professional but warm / direct / formal]
Key points: [bullet your points]
Length: [e.g., under 150 words]

Content repurposing

Here is a [blog post / report]: [paste content]

Repurpose this into:
1. A LinkedIn post (under 200 words, no hashtags)
2. Three tweet-length posts (under 280 characters each)
3. A 5-bullet email newsletter summary

Meeting prep

I have a meeting with [person/company] about [topic].
Here's what I know about them: [paste context]

Help me prepare:
1. Three smart questions I should ask
2. Two potential objections they might raise, and how I could respond
3. The one thing I want them to remember after this meeting

Compare with similar tools

Claude vs ChatGPT — ChatGPT has a larger ecosystem, image generation, and broader name recognition. For writing quality, document handling, and nuanced reasoning, most power users find Claude's outputs feel more considered and less generic. Claude's 200K context window is a practical advantage for anyone working with large documents.

Claude vs Gemini — Gemini integrates natively with Google Workspace (Docs, Sheets, Gmail, Drive). If your work lives in the Google ecosystem, that integration saves meaningful time. For pure writing quality and complex reasoning, Claude tends to be stronger.

Claude vs Perplexity — Perplexity has real-time web access and cites sources — it wins for any task requiring current information. Claude wins for deep analysis of documents you already have. Many people use both: Perplexity to find information, Claude to do something with it.