Choosing the Right Claude Model
Meet the Four Models
Claude comes in four models. Each is built for different kinds of work, and each uses your rate limit differently.
Haiku
- 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
- The daily driver.
- Sonnet 5 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
- A large reasoning specialist.
- Opus 5 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.
Fable
- The go-to for your largest, most important projects.
- Fable 5.1 is our most capable model, built for long, complex tasks.
- It can work through tasks more autonomously with fewer mid-task check-ins: describe the outcome you want, and it plans the steps and checks its own work along the way.
- It takes time to think through problems before answering, so responses take longer, and it uses the most of your rate limit.
- Fable is available on paid plans. You can select it from the model picker when a task needs it.
| Model | Rate limit use | Best for |
|---|---|---|
| Haiku | Lightest | Quick answers, summaries, and simple extraction — anything you want done instantly |
| Sonnet | Moderate | Coding, writing, analysis, and multi-step workflows — your versatile default |
| Opus | Heavy | Deep research and complex reasoning that genuinely needs sustained thinking |
| Fable | Heaviest | Your largest, most critical projects: long, complex tasks Claude works through with fewer check-ins |
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, Opus is heavy, and Fable uses the most.
Setting thinking and effort controls in order to customize the depth of reasoning Claude applies to a problem. The Effort setting in the model picker adjusts this directly:
- The default level is the right balance for most work
- Lower it for quicker answers that use less of your limit
- Save the highest setting for your hardest problems, since deeper thinking takes more time and uses more of your limit
When to Use Each Model
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 you’ll question, redirect, and build on as you go
- Complex work you’re doing in a live, back-and-forth session, where you want each answer sooner
- Biology and security work: Claude answers these topics with Opus even if you’ve picked Fable, so starting with Opus is simpler. To learn more, visit our help center.
- Problems where you’ve tested with Sonnet and it struggled
Use Fable for:
- Specialized tasks where accuracy is critical
- Long horizon tasks with many connected steps
- Outputs from dense source material: long documents, charts, technical diagrams
- Work where you’d rather describe the outcome and let Claude plan the steps
- Problems you’ve tested with Opus and it struggled
Examples in practice
| Task | Pick | Why |
|---|---|---|
| Summarizing articles | Haiku | Straightforward content extraction without complex reasoning |
| Debugging code | Sonnet | Exceptional coding capabilities, fast feedback, and clear bug identification |
| Analyzing complex research papers | Opus | Deep analysis across long specialized documents, including methodology critique and forward-looking insights |
| Building a working project from a rough idea | Fable | Plans the steps, checks its own work, and keeps working on long tasks with fewer mid-task check-ins |