Anthropic offers three Claude models: Haiku, Sonnet and Opus. Each model is optimised for a different type of task, from quick routine jobs to complex analyses of extensive documents. Which Claude model you use will help determine the quality and speed of your output.
What are Anthropic's Claude models?
Claude is available in three model lines, each offering a different balance between speed, capacity and cost. Haiku is the fastest and lightest model, Sonnet is the all-rounder for everyday professional use, and Opus is the most powerful model for complex and content-demanding tasks.
Each model runs on the same technical basis: a large language model trained on large amounts of text and refined via Anthropic's Constitutional AI method. The difference is in the scale, context window and degree of reasoning applied by the model. A broader explanation of how Claude works and what sets it apart from other AI assistants can be found in our article on what Claude AI is.
What is the Claude Haiku model?
Claude Haiku is the fastest Claude model, designed for tasks that require little reasoning but demand high speed or volume. Think of classifying texts, extracting structured data, answering simple queries and automating repetitive workflows. Haiku responds within seconds and has a context window of 200,000 tokens, sufficient for most business documents.
For professionals looking to deploy AI for process automation or high-volume simple tasks, Haiku is the most cost-effective Claude model. It is available via API and suitable for business integrations where speed outweighs reasoning depth.
What is the Claude Sonnet model?
Claude Sonnet is the all-rounder in the Claude model family and the most widely used model for everyday professional work. It is suitable for report writing and editing, data analysis, preparing presentations, drafting customer communications and developing marketing content.
Sonnet has a context window of one million tokens and delivers consistent output in tone and structure. This makes it practical for tasks where you want to use the output immediately without extensive post-processing.
The latest version is Claude Sonnet 4.6, which offers capabilities similar to previous Opus versions but is more responsive. For professionals who use Claude on a daily basis, Sonnet is the logical starting point. In the Claude AI course from LearnLLM learn how to use Sonnet effectively for your specific tasks and work context.
What is the Claude Opus model?
Claude Opus is the most capable Claude model and is intended for tasks that require in-depth analysis, complex reasoning or processing very large amounts of text. The latest version, Opus 4.7, was released on 16 April 2026 and is a direct successor to Opus 4.6 with improved performance on complex coding tasks, document analysis and long-running agentic workflows.
Opus 4.7 features a context window of one million tokens, allowing it to process extensive legal documents, voluminous reports or long research papers in a single session. The model is slower than Sonnet because it uses more computation time per answer. The output is deeper in content and more accurate for complex, open-ended questions. For strategic analyses, policy notes or tasks where errors are costly, that extra processing time is worthwhile.
Opus is available in Claude's paid subscriptions and via the API. It is not the model for everyday use, but the one you deploy when the task demands it.
What is the difference between the Claude models?
The difference between the Claude models lies in three things: speed, context window and depth of reasoning. Haiku is fast and light, Sonnet offers a good balance, Opus is slower but most capable at complex tasks.
| Model | Best for | Speed | Context window |
|---|---|---|---|
| Haiku 4.5 | Quick tasks, classification, automation | High | 200k tokens |
| Sonnet 4.6 | Daily professional use, writing, analysis | Average | 1M tokens |
| Opus 4.7 | Complex analyses, lengthy documents, strategic work | Low | 1M tokens |
In practice, we see at LearnLLM that most professionals start with Sonnet and switch to Opus only when they find that a specific task requires more depth of reasoning. Haiku is used almost exclusively for automated workflows or situations where speed is critical. Want to understand how Claude as a closed model compares to open source alternatives? Our article on open source versus closed AI provides insight into that.
Which Claude model is in the free version?
In the free version of Claude, you have access to a recent version of the Sonnet model. That is enough for most tasks to discover how Claude works and whether it fits your way of working.
The paid subscriptions give access to all three models, higher usage limits and priority on new features. Anthropic also offers a Claude Max subscription for intensive users who need higher limits. For enterprise integrations, all models are available through the API.
You can read how Claude compares to other AI tools and what considerations are relevant when choosing an AI assistant in our article on the different types of AI.
Which version of Claude should you choose?
For writing, e-mails, reports, customer communications and data analysis, Sonnet is the logical choice. The model delivers good output for most daily professional tasks and is responsive enough not to interrupt the workflow.
Choose Haiku if you want to automate a high volume of simple tasks, such as processing forms, categorising text or building automated workflows. Choose Opus 4.7 if you work with very long documents, complex strategic issues or demanding coding tasks where reasoning depth is critical.
Want to learn how to use the Claude models effectively in your daily work? In the Claude AI course from LearnLLM you will learn to work with prompts and advanced features, tailored to your field and role.
