Choosing the right Claude model: Haiku, Sonnet, and Opus
Learn when to use Haiku, Sonnet, or Opus to get better results and stay inside your rate limit. A practical guide to picking the right Claude model.
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- ProductClaude.ai
- Reading timeWatch time5minmin
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Claude comes in three models — Haiku, Sonnet, and Opus. Each is built for different kinds of work, and each uses your rate limit differently. Using Opus on a task Haiku could handle costs you tokens for no gain and slows you down in the process. In this guide you'll learn how to pick the Claude model that can most efficiently accomplish your task and keep you more comfortably within your rate limits.
Which models you have and how high your limit is both depend on your Claude account plan. Free includes Haiku and Sonnet; Pro and Max add Opus and more headroom.
Meet the three models
Claude comes in three versions. Think of them as different tools designed for different jobs.
| Model | Rate limit use | Best for |
|---|---|---|
| Haiku 4.5 | Lightest | Quick answers, summaries, and simple extraction — anything you want done instantly |
| Sonnet 4.6 | Moderate | Coding, writing, analysis, and multi-step workflows — your versatile default |
| Opus 4.6 | Heaviest | Deep research and complex reasoning that genuinely needs sustained thinking |
Haiku is fast and lightweight. Haiku 4.5 is built for everyday requests, and it rivals the reasoning capabilities of our Sonnet 4.0 model. When you need quick answers to simple questions, basic summaries, or synthesis, Haiku gets it done instantly. It's also the most efficient with your rate limit.
Sonnet is the daily driver. Sonnet 4.6 brings strong reasoning to the kind of work you do every day — coding, writing, analysis, research, and complex problem-solving. It's responsive enough for real-time collaboration and capable enough that most problems won't outgrow it. It also handles computer use, vision tasks, and document and spreadsheet creation well — making it a versatile default across a wide range of work. If you're not sure which model to pick, start here.
Opus is the large reasoning specialist. Opus 4.6 is exceptional for specialized complex tasks requiring advanced reasoning. It's built for problems that genuinely need deep thinking over time. It uses more of your rate limit, so you want to reserve it for tasks that really need it. Opus is available on Pro plans and above.
Understanding rate limits
Your rate limit caps how many tokens you can use in a given time window. The models consume tokens at different rates: Haiku is the lightest, Sonnet is moderate, and Opus uses the most because it reasons more deeply.
Simpler models like Haiku are more "efficient" with your limit — you can ask more with fewer tokens. Opus uses more tokens because it does more reasoning. But if you use Opus on a task that Haiku could handle, you're burning through your limit unnecessarily.
One thing that helps: both Sonnet 4.6 and Opus 4.6 feature extended thinking that is more adaptive, which means Claude automatically calibrates its reasoning depth to the problem. Simple questions get fast answers; complex ones get more thinking. This makes both models more token-efficient than their predecessors — even if you leave extended thinking on, easy questions don't eat into your limit as much as before.
When to use each model
To balance rate limits with efficiency, it's best to consider what kind of output you're looking for from Claude and choose your model accordingly.
Use Haiku for:
- Simple, straightforward questions with short answers
- Tasks where you just need a quick lookup or categorization
- Extracting specific information from text
- Simple summarization or synthesis
- Anything you want done instantly without complex reasoning
Use Sonnet for:
- Writing and content creation
- Coding tasks — debugging, writing new code, refactoring
- Analysis that needs reasoning but isn't extremely complex
- Customer support chatbots with context and nuance
- Multi-step problems and workflows
- Most "general purpose" work where you're not sure which model to use
Use Opus for:
- Deep research and analysis
- Complex reasoning that requires multiple steps
- Specialized tasks where accuracy is critical
- Problems where you've tested with Sonnet and it struggled
- Long documents requiring sustained concentration to understand
What this looks like in practice
Let's see how this plays out with a few common tasks.
| Task | Pick | Why |
|---|---|---|
| Debugging code | Sonnet | Exceptional coding capabilities, fast feedback, and clear bug identification |
| Summarizing articles | Haiku | Straightforward content extraction without complex reasoning |
| Analyzing complex research papers | Opus | Deep analysis across long specialized documents, including methodology critique and forward-looking insights |
Choosing models over time
One thing worth knowing: a new Claude version isn't a patch on the old one. Each release is a separate training run, which means a task that suited Opus 4.5 might sit more naturally with Sonnet 4.6, or the other way around.
This balance may shift with each release, so it's worth re-testing your assumptions when new versions arrive. Spend a few minutes running your go-to tasks across models. If you're on the free plan, upgrading gives you all three models and a higher rate limit. When a new model is released, you have more room to try everything.