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11---
22title: Choosing the right model
33url: https://platform.claude.com/docs/en/about-claude/models/choosing-a-model
4description: "Selecting the optimal Claude model for your application involves balancing three key considerations: capabilities, speed, and cost. This guide helps you make an informed decision based on your specific requirements."
4description: Choosing a Claude model means balancing capabilities, speed, and cost. This guide covers the questions to ask, two ways to pick a starting model, and how to test the choice.
55---
66
77## Establish key criteria
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1111* **Capabilities:** What specific features or capabilities will you need the model to have to meet your needs?
1212* **Speed:** How quickly does the model need to respond in your application? Claude Opus 5 and Claude Opus 4.8 support [fast mode](https://platform.claude.com/docs/en/build-with-claude/fast-mode) (research preview), which delivers up to 2.5x higher output speed at premium pricing.
1313* **Cost:** What's your budget for both development and production usage?
14* **Effort:** Recent Opus and Sonnet models support an [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort) that trades intelligence for latency and cost within a single model. Tuning effort is often a better lever than switching models. On Claude Opus 5, start with the default (`high`) and adjust up or down based on your evals. On Claude Opus 4.8 and Claude Opus 4.7, the `xhigh` effort level, between `high` and `max`, is the best setting for most coding and agentic use cases.
14* **Effort:** Several Claude models support an [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort) that trades intelligence for latency and cost within a single model. Tuning effort is often a better lever than switching models. On Claude Fable 5.1 and Claude Opus 5, start with the default (`high`) and adjust up or down based on your evals. On Claude Opus 4.8 and Claude Opus 4.7, the `xhigh` effort level, between `high` and `max`, is the best setting for most coding and agentic use cases.
1515
16Knowing these answers in advance will make narrowing down and deciding which model to use much easier.
17
1816***
1917
2018## Choose the best model to start with
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45432. [Optimize your prompts](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-opus-5) for this model.
46443. Evaluate if performance meets your requirements.
47454. Consider increasing efficiency by lowering [effort](https://platform.claude.com/docs/en/build-with-claude/effort) or downgrading models over time with greater workflow optimization.
465. If your evals at `xhigh` or `max` effort still fall short on demanding reasoning or long-horizon agentic work, move to [Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/whats-new-fable-5-1).
4847
4948This approach is best for:
5049
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5453* Applications where accuracy outweighs cost considerations
5554* Advanced coding and high-autonomy agentic work
5655
57<Note>
58 The [effort parameter](https://platform.claude.com/docs/en/build-with-claude/effort) defaults to `high` on Claude Opus 5 and Claude Opus 4.8, including in Claude Code and the Messages API. On Claude Opus 5, start at the default and step up to `xhigh` for the most demanding coding and agentic work. On Claude Opus 4.8, use `xhigh` for coding, high-autonomy work, and the most intelligence-demanding tasks.
59</Note>
56**Claude Opus 5** (`claude-opus-5`) is built for complex agentic coding and enterprise work, with deep reasoning, long-horizon tasks, and test-time compute scaling.
6057
61**Claude Opus 5** (`claude-opus-5`) is a step-change improvement over Claude Opus 4.8, strong on deep reasoning, agentic and long-horizon tasks, and test-time compute scaling. Claude Opus 5 supports a 1M token context window by default and up to 128k output tokens, and is priced at $5 USD per million input tokens and $25 USD per million output tokens.
58**Claude Fable 5.1** (`claude-fable-5-1`) is Anthropic's most capable widely released model. It extends Claude Fable 5 with stronger long-running agentic coding, knowledge work, and research at the same input and output prices, with cache reads at a quarter of the cost. **Claude Mythos 5.1** (`claude-mythos-5-1`) offers the same capabilities to [Project Glasswing](https://anthropic.com/glasswing) participants only. Both models use always-on [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking). See [What's new in Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/whats-new-fable-5-1) for details.
6259
63**Claude Fable 5** (`claude-fable-5`) is Anthropic's most capable widely released model, delivering next-generation intelligence for long-running agents. **Claude Mythos 5** (`claude-mythos-5`) is available through [Project Glasswing](https://anthropic.com/glasswing). Both models support a 1M token context window by default, up to 128k output tokens, and always-on [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/thinking). See [Introducing Claude Fable 5 and Claude Mythos 5](https://platform.claude.com/docs/en/models/fable-5/introducing-claude-fable-5-and-claude-mythos-5) for launch details.
60Claude Fable 5 and Claude Mythos 5 are also available. See [Introducing Claude Fable 5 and Claude Mythos 5](https://platform.claude.com/docs/en/models/fable-5/introducing-claude-fable-5-and-claude-mythos-5) for details. For context windows, output limits, and prices, see the [model comparison table](https://platform.claude.com/docs/en/models/overview#latest-models-comparison).
6461
65Claude Fable 5 and Claude Mythos 5 are priced at $10 USD per million input tokens and $50 USD per million output tokens.
66
6762## Model selection matrix
6863
69| When you need... | Consider starting with... | Example use cases |
70| ------------------------------------------------------------------------------------------------------------ | ------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- |
71| The highest available capability | Claude Fable 5 | Long-running agents, deep reasoning, long-horizon agentic tasks, advanced research |
72| Complex agentic coding and enterprise work | Claude Opus 5 | Multihour autonomous coding agents, large-scale refactoring, complex systems engineering, advanced research, knowledge work, vision-heavy workflows, computer use |
73| Frontier intelligence at scale, built for coding, agents, and enterprise workflows | Claude Sonnet 5 | Code generation, data analysis, content creation, visual understanding, agentic tool use |
74| Near-frontier performance with lightning-fast speed and extended thinking at the most economical price point | Claude Haiku 4.5 | Real-time applications, high-volume intelligent processing, cost-sensitive deployments needing strong reasoning, sub-agent tasks |
64Most workloads start with Claude Opus 5.
7565
66| When you need... | Consider starting with... | Example use cases |
67| ------------------------------------------------------------------------- | ------------------------- | --------------------------------------------------------------------------------------------------------------------------------- |
68| The highest available capability | Claude Fable 5.1 | Agent sessions that run for hours, multistep deep research, analysis carried through to a finished document, spreadsheet, or deck |
69| Complex agentic coding and enterprise work | Claude Opus 5 | Multihour autonomous coding agents, large-scale refactoring, complex systems engineering, vision-heavy workflows, computer use |
70| Speed and capability for everyday coding, agent, and enterprise workloads | Claude Sonnet 5 | Code generation, data analysis, content creation, visual understanding, agentic tool use |
71| The lowest latency and price, with extended thinking | Claude Haiku 4.5 | Real-time applications, high-volume intelligent processing, cost-sensitive deployments needing strong reasoning, sub-agent tasks |
72
7673***
7774
7875## Decide whether to upgrade or change models
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10299 See detailed specifications and pricing for the latest Claude models
103100 </Card>
104101
102 <Card title="What's new in Claude Fable 5.1" icon="sparkle" href="https://platform.claude.com/docs/en/models/fable-5-1/whats-new-fable-5-1">
103 Built for demanding reasoning and long-horizon agentic work
104 </Card>
105
105106 <Card title="What's new in Claude Opus 5" icon="sparkle" href="https://platform.claude.com/docs/en/models/opus-5/whats-new-opus-5">
106 Explore the latest improvements in Claude Opus 5
107 Explore the improvements in Claude Opus 5
107108 </Card>
108109
109110 <Card title="What's new in Claude Sonnet 5" icon="sparkle" href="https://platform.claude.com/docs/en/models/sonnet-5/whats-new-sonnet-5">
110 The best combination of speed and intelligence
111 For everyday workloads that balance speed and capability
111112 </Card>
112113
113114 <Card title="Start building" icon="code" href="https://platform.claude.com/docs/en/get-started">