Complete Claude guide: installation, use and optimisation for maximum results

Artificial intelligence has become a daily work tool for millions of people around the world. The transformation brought by artificial intelligence affects every field, from programming to marketing, and Claude, developed by Anthropic, is among the most appreciated AI platforms available today.

Claude is not just a chatbot. It is an advanced AI assistant capable of writing code, analysing documents, translating texts, explaining complex concepts and solving problems that require deep reasoning. Its latest versions, including Opus 4.7, released in April 2026, consistently place it among the most capable AI models available to the public.

This guide covers everything you need to know about Claude: from creating an account and installing it, to advanced use, prompt optimisation and integration with other work tools.

Complete Claude guide: installation, use and optimisation for maximum results

Claude is available in several forms: as a web app, as a desktop app, as an extension for code editors and as an API for developers. Whatever your level of experience, there is a way to access and use it effectively.

Before moving on to installation and use, it is important to understand what sets Claude apart from other AI models and why it deserves a place in your workflow.

We will go through all the basics step by step, from fundamental notions to the advanced techniques used by professionals and developers.

What Claude is and who develops it

Claude is a family of large language models (LLMs) developed by Anthropic, an AI research company founded in 2021 and based in San Francisco. Anthropic's founders, including Dario Amodei and Daniela Amodei, left OpenAI with the goal of putting AI safety at the centre of the development process.

The philosophy behind Claude is called Constitutional AI, a method in which the model is trained to follow a set of ethical principles and avoid harmful behaviour. This is one of the fundamental differences from other AI models, which use different alignment approaches.

The name "Claude" is a reference to the mathematician Claude Shannon, the father of information theory, a choice that reflects the company's focus on rigour and scientific grounding.

The Claude models available in 2026

In 2026, the Claude family comprises three main model lines, each optimised for a particular balance of speed, cost and capability. If this is your first contact with the platform, first read our introductory guide to Claude AI for an overview.

The first line is Claude Haiku 4.5, the fastest and most affordable model, ideal for simple tasks and applications that need instant responses. The second line is Claude Sonnet 4.6, the balanced model, with excellent performance for the vast majority of tasks at a reasonable cost.

The third line is Claude Opus 4.7, the most powerful model available, recommended for complex programming tasks, advanced analysis and projects that require deep reasoning.

Each model has a context window of 200,000 tokens, which means it can process extremely long documents, entire codebases or extended conversations without losing context.

The differences between Haiku, Sonnet and Opus

Choosing the right model depends on the type of task you want to accomplish. Haiku is recommended for simple classifications, short answers and applications that process large volumes of requests on a limited budget.

Sonnet is the best choice for writing, document analysis, medium-complexity code generation and extended conversations. It is the model Anthropic recommends as a starting point for most users.

Opus is recommended for complex mathematical problems, advanced code, multi-document analysis and any task where the quality of the answer matters more than speed or cost. Opus 4.7 also processes images at resolutions of up to 2,576 pixels on the long side, a major improvement over previous versions.

How to create a Claude account

Creating a Claude account is free and takes less than two minutes. Anthropic offers a free plan with limited access, enough to understand the platform's capabilities before deciding whether you want to invest in a paid subscription.

Go to claude.ai from any browser and you will be greeted by the sign-up page. You can create an account using your email address, your Google account or your Apple account.

After signing up, you go straight to the main conversation interface. No additional setup is needed for basic use.

Available plans and prices

The free plan gives access to the Claude models with a limited number of messages per day. It is enough for occasional use, but you will quickly notice the limits if you use it heavily.

The Pro plan costs 20 dollars a month and gives priority access to all models, including Opus, a much larger number of messages and access to advanced features such as Projects and persistent memory.

The Max plan costs 100 dollars a month and is aimed at users who need very large volumes of conversations. The Team and Enterprise plans are intended for organisations and offer collaboration features, SSO, administrative controls and dedicated confidentiality agreements.

How to log in and set up your profile

After creating your account, go to Settings in the left-hand menu to personalise the experience. You can set your preferred language, response style and the standing instructions Claude should follow in all your conversations.

The Custom Instructions section is especially valuable. Here you can specify your profession, the level of detail you want in answers, your preferred tone and any other preferences you do not want to repeat in every conversation.

For example, if you are a programmer and use Python, you can specify in the custom instructions that you prefer Python over other languages and that you always want commented code. Claude will take these preferences into account automatically.

How to install Claude on different platforms

Claude is accessible from almost any device and operating system. Anthropic has invested heavily in expanding the access points, so you can use the assistant wherever you work.

From the browser to the terminal, from the phone to the code editor, Claude can be integrated into your workflow without major interruptions.

Each platform has its own characteristics, but they all share the same AI model and the same basic capabilities.

Claude in the browser

The simplest way to access it is through the browser, at claude.ai. It requires no installation and works on any operating system: Windows, macOS, Linux or ChromeOS.

The web interface is complete and gives access to all features: file uploads, artifact generation, access to Projects and conversation history. For occasional users, or those who work on several computers, this is the recommended option.

Chrome and Edge also let you install claude.ai as a PWA (Progressive Web App), that is, a desktop shortcut that opens Claude in a dedicated window, without the browser's navigation bar.

The Claude desktop app

Anthropic has released native apps for macOS and Windows, available for download from claude.ai/download. The desktop app offers a few advantages over the browser version: faster startup, native notifications and better integration with the operating system.

On macOS, the app integrates with the menu bar and can be opened quickly with a configurable key combination. On Windows, the app appears in the taskbar and can be called up from any application through the global shortcut.

The desktop app automatically syncs all conversations and projects with your account, so there are no functional differences compared with the web version.

Claude on mobile (iOS and Android)

The Claude mobile apps are available for free in the App Store (iOS) and the Google Play Store (Android). They offer the same conversation experience as the desktop version, optimised for small screens and touch navigation.

On mobile, Claude can access the camera to analyse images in real time. Photograph a mathematical equation, a recipe, a printed document or anything else and Claude will analyse the content directly.

The voice dictation feature lets you send spoken messages, turning Claude into a voice assistant that answers in text or, on some devices, through speech synthesis.

Installing Claude Code (CLI)

Claude Code is the command-line interface for developers, which lets you interact with Claude directly from the terminal and integrate it with code projects. It is programmers' preferred tool because it understands the context of the codebase and can make changes directly in files.

Installation is done through npm. Open a terminal and run:

npm install -g @anthropic-ai/claude-code

After installation, log in with the command:

claude login

You will be redirected to the browser to authenticate. After confirmation, you can use the claude command from any directory of your project. Claude Code automatically reads the files in the directory and understands the project structure without you having to copy the code manually.

Claude Code is also available as an extension for VS Code, JetBrains (IntelliJ, PyCharm, WebStorm) and other editors compatible with the LSP protocol.

How to use Claude efficiently

Simply accessing Claude does not guarantee good results. The quality of the answers depends largely on the quality of the questions and instructions you give. Users who understand how to communicate clearly with an AI model get much better results than those who use vague questions.

There are a few basic principles that turn an ordinary user into an effective one. These principles are simple, but their impact is major.

The more time you invest in phrasing your request clearly, the less time you will spend correcting and adjusting the answers.

The web interface step by step

When you first open claude.ai, you see a central text box and a few suggestions for common conversations. Type your request in the text box and press Enter or the send button.

On the left of the screen is the navigation panel with the conversation history and the projects you have created. Conversations are saved automatically and can be searched by keyword. You can rename any conversation by clicking its title for better organisation.

The file attachment button (the paperclip icon) lets you upload PDF documents, images, CSV files, source code and other formats. The size limit per file is 10 MB for images and 30 MB for text documents.

How to write clear and effective prompts

An effective prompt contains four elements: the context (who you are and what you want), the exact task (what Claude has to do), the desired format (how you want the answer) and any constraints (limits on length, tone, language).

An example of a weak prompt: "Write an email." An example of a good prompt: "Write a professional follow-up email to a client who has not replied to our SEO services offer sent 5 days ago. The tone should be friendly but firm, maximum length 150 words, in Romanian."

The difference in the quality of the answers between the two phrasings is dramatic. The more specific the prompt, the more precise and useful the answer will be.

Using projects and memory

The Projects feature lets you create dedicated workspaces for different projects or fields. Each project can contain reference files, specific instructions and an organised conversation history.

If you manage a WordPress site, you can create a dedicated project in which to upload the theme, the configuration files and a description of the project. All the conversations in that project will automatically benefit from this context, without you having to re-explain the situation each time.

The persistent memory feature (available on paid plans) lets Claude retain information about you between conversations. You can say explicitly "Remember that I work with PHP 8.2 and that I prefer anonymous functions over separate classes" and Claude will take that into account in future conversations.

Uploading files and images

Claude can analyse a wide range of file types. PDF documents are especially useful for extracting information from contracts, reports or technical manuals. CSV files allow data analysis and the generation of insights without any programming knowledge.

Images are processed with remarkable accuracy: Claude can describe the content, extract text (OCR), analyse charts and diagrams or identify objects and people. Opus 4.7 processes images at resolutions of up to 2,576 pixels, allowing detailed analysis of high-resolution photos.

Source code files are understood in depth: Claude can explain what the code does, identify bugs, suggest optimisations and rewrite entire sections while respecting the existing style and conventions.

Claude integrations with other tools

Claude's real power shows when it is integrated into existing workflows. Anthropic has developed an extensive ecosystem of integrations that let you use Claude alongside the tools you already use.

Whether you are a programmer, a marketer, a data analyst or a project manager, there is a Claude integration that can automate or speed up the repetitive tasks in your work.

The most valuable integrations are those with code editors, with the API for automations and with productivity platforms.

The VS Code extension

The Claude extension for Visual Studio Code is installed directly from the VS Code Marketplace by searching for "Claude" or "Anthropic". Once installed, Claude appears as a side panel in the editor.

The extension understands the context of the file currently open, of the whole project and of the errors in the console. You can select a piece of code and ask directly "Explain what this code does" or "Rewrite this function more efficiently" without copying anything manually.

The AI autocomplete feature suggests how to continue the code as you type, similar to GitHub Copilot, but powered by Claude models. Integration with the built-in terminal lets Claude see compilation errors and suggest fixes instantly.

The Anthropic API for developers

The Anthropic API lets you integrate Claude into your own applications, websites or automations. API access is obtained by creating an API key at console.anthropic.com. If you are not familiar with the concept, first read our guide to how online optimisation works to understand the wider context of automations.

A basic API request looks like this in Python:

import anthropic

client = anthropic.Anthropic(api_key="cheia_dvs_api")

message = client.messages.create( model="claude-opus-4-7", max_tokens=1024, messages=[ {"role": "user", "content": "Explică ce este SEO în 3 propoziții."} ] )

print(message.content[0].text)
The API supports streaming (receiving the answer word by word rather than all at once), tool calls (tool use), vision (image analysis) and prompt caching to cut costs by up to 90%.

Integrations with Google Workspace and Microsoft 365

Claude integrates with Google Docs, Sheets and Gmail through browser extensions or through Zapier and Make (formerly Integromat) connectors. You can select text in a Google document and send it directly to Claude for rewording, translation or expansion. If you use Google Analytics 4, Claude can interpret exported data and generate performance reports in seconds.

For Microsoft 365, there are similar integrations with Word, Excel and Outlook. In Excel, Claude can analyse the data in the spreadsheet, generate complex formulas and interpret the automatically generated charts.

Through automation platforms such as Zapier, you can create no-code workflows: for example, "When I receive an email with subject X, send its content to Claude and save the answer in Notion".

Claude in AI agents and MCP

Model Context Protocol (MCP) is an open standard developed by Anthropic that lets Claude interact with external tools and data sources. Through MCP, Claude can read and write files, access databases, search the web and control other applications.

Claude Code uses MCP extensively to access the file system, run terminal commands and interact with external APIs directly from the conversation. You can ask Claude to create a file, run tests or make a Git commit, all without leaving the chat interface.

AI agents built on Claude can carry out tasks autonomously: web research, report writing, data monitoring and automatic notifications. This is Anthropic's main direction of development for 2026 and 2027.

How to optimise prompts for better results

Prompt optimisation (prompt engineering) is the skill of phrasing instructions that extract the maximum value from an AI model. It does not require programming knowledge, but it does require attention to detail and an understanding of how language models work.

There are simple techniques that can completely transform the quality of the answers you get, regardless of the complexity of the task. Applying these techniques consistently can greatly reduce the time spent on corrections and iterations.

Prompt engineering is not about tricks or "magic". It is about clear communication, the same way you would communicate with a new colleague who does not know the project's context.

The structured prompt technique

Structured prompts split the request into clear sections: role, context, task, format and constraints. This structure removes ambiguity and guides the model towards the desired answer.

Example of a structured prompt: "Role: You are an SEO copywriter with 10 years of experience. Context: I am writing for a WordPress security blog. Task: Write an introduction about brute force attacks on WordPress. Format: Continuous paragraph, no lists. Tone: Professional, slightly alarmist."

Compared with "Write an introduction about brute force attacks", the structured prompt will produce a text that is genuinely usable on the first try.

Using context and examples

Providing concrete examples (few-shot prompting) is one of the most effective techniques. Instead of describing what you want, show the model an example of input and output, and it will understand exactly the format and style expected.

If you want Claude to classify emails, provide 3-5 examples of emails that have already been classified before sending the email you want classified. The accuracy will be much higher than with a generic classification instruction.

Document context is just as important. If you are analysing a contract, upload the complete contract, not just the problematic paragraph. Claude will understand the tone, terminology and intent of the document better if it has access to the whole context.

System instructions (system prompt)

The system prompt is an instruction invisible to the user, placed before the conversation, that defines the model's personality, limits and behaviour. It is used mainly by developers who build applications on the Claude API.

A well-written system prompt can turn Claude into a specialised assistant: an accounting expert who answers only tax questions, a technical support chatbot for a specific product or a teacher who explains concepts at high-school level.

In the web interface, the Custom Instructions feature in Settings plays the same role as the system prompt. Invest a few minutes in setting up these instructions and every future conversation will benefit from them automatically.

Prompt caching for API savings

Prompt caching is an API feature that lets you store repetitive portions of prompts in cache, reducing costs by up to 90% and response times by up to 85%. It matters for applications that use long documents or extended system instructions.

It works by marking, with a special parameter, the portions of text that stay identical between requests. On the first requests, these portions are processed normally. On later requests, Claude retrieves them from the cache, saving input tokens.

Implementation is simple in Python or JavaScript and quickly becomes cost-effective for any application with moderate volumes of API requests.

Advanced Claude features

Beyond simple question-and-answer conversations, Claude offers advanced features that turn it from a chat assistant into a complex work tool. These features are available on paid plans and through the API.

Users who explore these features often discover that Claude can replace or augment specialised tools they currently use.

We will review the most valuable advanced features and how you can integrate them into your daily work.

Artifacts and visual content generation

The Artifacts feature lets Claude generate content that can be viewed and exported separately from the conversation: complete HTML pages, interactive React code, SVG diagrams, formatted Markdown documents and more.

When you ask Claude to generate a web page or an interface component, it appears in a separate panel to the right of the conversation, where you can preview it in real time and download it. You no longer have to copy the code and open it manually in a browser.

Artifacts is especially useful for rapid interface prototyping, generating HTML reports, creating presentations and visualising data in interactive charts.

Document and image analysis

Claude can analyse several documents at once and synthesise the information from all of them. If you have three quarterly financial reports and want a comparison, you can upload all three in a single conversation and ask for the comparative analysis.

Image analysis includes text extraction (OCR), interpretation of charts and diagrams, analysis of product photos, reading of technical data sheets and identification of design elements. Opus 4.7 has greatly improved its vision capabilities compared with previous versions, processing images at three times higher resolutions.

Scanned documents, even those of medium quality, can be processed with high accuracy, removing the need to retranscribe the information manually.

Searching the internet

Paid plans include access to real-time web search, allowing Claude to access up-to-date information beyond its training date. When you enable web search, Claude can check current facts, current prices, recent news and any other information that changes frequently.

The feature is activated automatically when Claude detects that the question requires recent information, or it can be activated manually by explicitly mentioning the need for up-to-date information.

The sources used in the answer are cited explicitly, allowing independent verification of the information. This is an important difference from answers based solely on training data, which cannot be verified at the source.

Using MCP and external tools

Through the Model Context Protocol, Claude can be extended with custom tools: access to an internal database, a CRM system, an external API or any other data source. MCP servers are relatively simple to implement in Python or TypeScript and can be shared between teams.

There is already an ecosystem of public MCP servers for popular services: GitHub, Slack, Notion, Google Drive, Jira and many more. You can install these servers in Claude Code or in the desktop app and interact with these services directly from the conversation.

Combining MCP with autonomous AI agents opens up possibilities for advanced automation, where Claude can run complex workflows without human intervention at every step.

Security and privacy tips

Any cloud tool raises legitimate questions about privacy and data security. Claude processes text on Anthropic's servers, which means the information sent in conversations ends up on the company's infrastructure.

Before using Claude in a professional context, it is important to understand what data is processed, how it is stored and what your control options are.

Anthropic publishes detailed privacy policies and has obtained various security certifications, but the final responsibility for the type of data shared remains with the user.

What data Claude processes

All the text entered in conversations, the files uploaded and the images sent are processed on Anthropic's servers. By default, conversations are stored in your account history and can be used by Anthropic to improve its models, unless you have explicitly disabled this option.

Enterprise plans include data processing agreements (DPAs) and the option to completely disable the use of data for training. If you work with sensitive business data, it is recommended that you also read the guide to responding to security incidents to understand how to react in the event of a breach.

Technical metadata (IP address, the browser used, response times) is collected as in any standard web service and is described in Anthropic's privacy policy.

How not to enter sensitive data

The basic rule is never to enter into Claude personal data of customers or any information protected by a confidentiality agreement. Use two-factor authentication (2FA) on your Claude account for an extra layer of access protection.

You can anonymise data before sending it: replace real names with "Client A", email addresses with generic examples and real amounts with approximate values. Claude will still be able to help you with the analysis or formatting without having access to the real data.

For source code, always check whether the snippet you send contains sensitive business logic. Malicious code can sometimes be introduced through compromised dependencies, and Claude can help analyse and detect it without you having to expose the entire codebase.

Privacy settings

Go to Settings > Privacy in your Claude account to manage the available options. You can disable the use of conversations for model training (recommended if you discuss business information), you can delete the conversation history and you can manage the third-party apps connected to the account.

The data export feature lets you download all stored conversations in JSON format, useful if you want to archive or migrate your conversation history.

For organisations, Enterprise account administrators can centrally manage data retention policies, user permissions and authorised integrations.

Claude vs. other AI models compared

The AI model market is extremely competitive in 2026, with several major players releasing new versions every few months. Each model has strengths and weaknesses, and the right choice depends on the specific use case.

There is no absolutely "best" model. There are models better suited to certain tasks, at certain prices and with certain characteristics.

The comparisons below are based on public benchmarks and users' practical experience, not on the manufacturers' marketing claims.

Claude vs. ChatGPT (OpenAI)

ChatGPT is the best-known AI assistant, with a big lead over Claude in public recognition. GPT-4o and GPT-4.5 are powerful models, especially for integration with the Microsoft ecosystem (Copilot in Word, Excel, Teams).

Claude excels over GPT in long, coherent writing tasks, following complex instructions and ethical reasoning. Claude's 200,000-token context window greatly exceeds GPT's standard limits, which is basic for modern SEO strategies that require analysing large volumes of content.

ChatGPT has the advantage of a more mature plugin ecosystem and native integration with DALL-E for image generation, a capability Claude does not offer. The choice between the two often depends on personal preference and the integrations needed.

Claude vs. Gemini (Google)

Gemini is Claude Opus's main competitor at the top end of the market. Gemini excels in integration with Google services (Search, Workspace, YouTube) and in tasks that benefit from access to real-time data from the Google index.

Claude is generally appreciated for its superior writing quality, for the coherence of long answers and for more predictable behaviour in complex reasoning tasks. For users who follow the impact of AI on search results, Google AI Overviews remains a basic topic to understand.

For users already invested in the Google ecosystem, Gemini may be more convenient. For users who emphasise the quality of the generated text and precise instruction-following, Claude is often the preference.

When to choose Claude

Claude is the best choice when you work with long documents (contracts, reports, extensive codebases) thanks to the 200,000-token context window. It is also recommended for quality professional writing and for applications where predictable, safe behaviour is critical.

Developers building AI applications appreciate the Claude API for its clear documentation, its advanced tool use features and prompt caching, which greatly reduces operating costs. If you want to create content that generates customers, Claude can be a powerful ally in the editorial process.

In education and research, Claude is appreciated for its tendency to admit uncertainty when it does not know an answer for certain. Knowing the priority SEO trends helps you use Claude strategically to produce optimised content.

Conclusion

Claude is one of the most capable and best-balanced AI tools available in 2026. From the individual user who wants a writing assistant to the developer building complex applications on the API, the platform offers a solution for every level of need.

The key to using it effectively is understanding that Claude is a tool that amplifies your capabilities, not one that replaces them. The more context and clarity you bring to your interactions with it, the more valuable the results will be.

Investing in understanding the advanced features, setting up custom instructions and exploring the integrations relevant to your work will bring a large return in productivity and in the quality of the work produced.

Anthropic continues to release regular updates, each version bringing major improvements in capability and efficiency. Following the release notes and experimenting with the new features is the best way to keep up with what Claude can do for you.

Source references

• Documentația Claude
• Claude Code, documentația oficială
• Documentația Claude: scrierea instrucțiunilor