Models overview changedmodels/overview
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2525If you're unsure which model to use, start with [Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/overview) for most workloads. Use [Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/overview) for demanding reasoning and long-horizon agentic work, or when your evals on Claude Opus 5.5 at higher effort still fall short. All current models support text and image input, text output, multilingual capabilities, vision, and tool use. Each model's page lists the platforms it's available on.
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27| Feature | Claude Fable 5.1 | Claude Opus 5.5 | Claude Sonnet 5 | Claude Haiku 4.5 |
28| :-------------------------------------------------------------------------------------------------------- | :-------------------------------------------------------------------------------- | :------------------------------------------------------------------------------ | :------------------------------------------------------------------------------ | :-------------------------------------------------------------------------------- |
29| Description | For demanding reasoning and long-horizon agentic work | For long-running agentic coding and knowledge work | The best combination of speed and intelligence | The fastest model with near-frontier intelligence |
30| Model page | [Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/overview) | [Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/overview) | [Claude Sonnet 5](https://platform.claude.com/docs/en/models/sonnet-5/overview) | [Claude Haiku 4.5](https://platform.claude.com/docs/en/models/haiku-4-5/overview) |
31| Comparative latency | Slower | Moderate | Fast | Fastest |
32| [Pricing](https://platform.claude.com/docs/en/about-claude/pricing) | $10 / input MTok, $50 / output MTok | $4 / input MTok, $20 / output MTok | $2 / input MTok, $10 / output MTok | $1 / input MTok, $5 / output MTok |
33| Claude API ID | `claude-fable-5-1` | `claude-opus-5-5` | `claude-sonnet-5` | `claude-haiku-4-5-20251001` |
34| [Thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) | Adaptive (always on) | Adaptive (always on) | Adaptive | Extended |
35| [Default effort](https://platform.claude.com/docs/en/build-with-claude/effort) | `high` | `medium` | `high` | Not supported |
36| [Context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) | 1M tokens | 1M tokens | 1M tokens | 200K tokens |
37| Max output | 128K tokens | 128K tokens | 128K tokens | 64K tokens |
38| Reliable knowledge cutoff | Jun 2026 | Jun 2026 | Jan 2026 | Feb 2025 |
39| Training data cutoff | Jun 2026 | Jun 2026 | Jan 2026 | Jul 2025 |
40| [Retirement](https://platform.claude.com/docs/en/about-claude/model-deprecations) | Not sooner than September 1, 2027 | Not sooner than September 22, 2027 | Not sooner than June 30, 2027 | Not sooner than October 15, 2026 |
41| Claude API alias | `claude-fable-5-1` | `claude-opus-5-5` | `claude-sonnet-5` | `claude-haiku-4-5` |
42| [Amazon Bedrock ID](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock) | `anthropic.claude-fable-5-1` | `anthropic.claude-opus-5-5` | `anthropic.claude-sonnet-5` | `anthropic.claude-haiku-4-5` |
43| [Google Cloud ID](https://platform.claude.com/docs/en/build-with-claude/claude-on-vertex-ai) | `claude-fable-5-1` | `claude-opus-5-5` | `claude-sonnet-5` | `claude-haiku-4-5@20251001` |
44| [Microsoft Foundry ID](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry) | `claude-fable-5-1` | `claude-opus-5-5` | `claude-sonnet-5` | `claude-haiku-4-5` |
45| [Claude Platform on AWS ID](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws) | `claude-fable-5-1` | `claude-opus-5-5` | `claude-sonnet-5` | `claude-haiku-4-5` |
27| Feature | Claude Fable 5.1 | Claude Opus 5.5 | Claude Sonnet 5.5 | Claude Haiku 4.5 |
28| :-------------------------------------------------------------------------------------------------------- | :-------------------------------------------------------------------------------- | :------------------------------------------------------------------------------ | :---------------------------------------------------------------------------------- | :-------------------------------------------------------------------------------- |
29| Description | For demanding reasoning and long-horizon agentic work | For long-running agentic coding and knowledge work | The best combination of speed and intelligence | The fastest model with near-frontier intelligence |
30| Model page | [Claude Fable 5.1](https://platform.claude.com/docs/en/models/fable-5-1/overview) | [Claude Opus 5.5](https://platform.claude.com/docs/en/models/opus-5-5/overview) | [Claude Sonnet 5.5](https://platform.claude.com/docs/en/models/sonnet-5-5/overview) | [Claude Haiku 4.5](https://platform.claude.com/docs/en/models/haiku-4-5/overview) |
31| Comparative latency | Slower | Moderate | Fast | Fastest |
32| [Pricing](https://platform.claude.com/docs/en/about-claude/pricing) | $10 / input MTok, $50 / output MTok | $4 / input MTok, $20 / output MTok | $2 / input MTok, $10 / output MTok | $1 / input MTok, $5 / output MTok |
33| Claude API ID | `claude-fable-5-1` | `claude-opus-5-5` | `claude-sonnet-5-5` | `claude-haiku-4-5-20251001` |
34| [Thinking](https://platform.claude.com/docs/en/build-with-claude/thinking) | Adaptive (always on) | Adaptive (always on) | Adaptive | Extended |
35| [Default effort](https://platform.claude.com/docs/en/build-with-claude/effort) | `high` | `medium` | `high` | Not supported |
36| [Context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) | 1M tokens | 1M tokens | 1M tokens | 200K tokens |
37| Max output | 128K tokens | 128K tokens | 128K tokens | 64K tokens |
38| Reliable knowledge cutoff | Jun 2026 | Jun 2026 | Jun 2026 | Feb 2025 |
39| Training data cutoff | Jun 2026 | Jun 2026 | Jun 2026 | Jul 2025 |
40| [Retirement](https://platform.claude.com/docs/en/about-claude/model-deprecations) | Not sooner than September 1, 2027 | Not sooner than September 22, 2027 | Not sooner than September 28, 2027 | Not sooner than October 15, 2026 |
41| Claude API alias | `claude-fable-5-1` | `claude-opus-5-5` | `claude-sonnet-5-5` | `claude-haiku-4-5` |
42| [Amazon Bedrock ID](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock) | `anthropic.claude-fable-5-1` | `anthropic.claude-opus-5-5` | `anthropic.claude-sonnet-5-5` | `anthropic.claude-haiku-4-5` |
43| [Google Cloud ID](https://platform.claude.com/docs/en/build-with-claude/claude-on-vertex-ai) | `claude-fable-5-1` | `claude-opus-5-5` | `claude-sonnet-5-5` | `claude-haiku-4-5@20251001` |
44| [Microsoft Foundry ID](https://platform.claude.com/docs/en/build-with-claude/claude-in-microsoft-foundry) | `claude-fable-5-1` | `claude-opus-5-5` | `claude-sonnet-5-5` | `claude-haiku-4-5` |
45| [Claude Platform on AWS ID](https://platform.claude.com/docs/en/build-with-claude/claude-platform-on-aws) | `claude-fable-5-1` | `claude-opus-5-5` | `claude-sonnet-5-5` | `claude-haiku-4-5` |
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4747* **Comparative latency:** Relative to the current lineup. Actual latency depends on prompt length, output length, and thinking effort.
4848* **Pricing:** Base price per million tokens. Batch API requests are 50% off; prompt cache reads cost 10% of the base input price (2.5% on Claude Fable 5.1 and Claude Mythos 5.1, 5% on Claude Opus 5.5). See Pricing for cache writes, long-context, and per-platform pricing.
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5050* **Thinking:** Adaptive thinking lets the model decide how much to think, steered by effort. Extended thinking is the manual thinking.type “enabled” + budget\_tokens mode on earlier models; it is deprecated on Claude Opus 4.6 and Claude Sonnet 4.6 and not accepted on later models.
5151* **Default effort:** The effort parameter’s default on the Claude API. Set effort explicitly to use a different level.
5252* **Context window:** 1M tokens is roughly 555k words or 2.5M Unicode characters on the current tokenizer (introduced with Claude Opus 4.7); models before it fit about 750k words in 1M tokens. 200k tokens is roughly 150k words.
53* **Max output:** Synchronous Messages API limit. On the Message Batches API, Claude Opus 5.5, Claude Opus 5, Claude Sonnet 5, Claude Opus 4.8, Claude Opus 4.7, Claude Opus 4.6, and Claude Sonnet 4.6 support up to 300k output tokens with the output-300k-2026-03-24 beta header.
53* **Max output:** Synchronous Messages API limit. On the Message Batches API, Claude Opus 5.5, Claude Opus 5, Claude Sonnet 5.5, Claude Sonnet 5, Claude Opus 4.8, Claude Opus 4.7, Claude Opus 4.6, and Claude Sonnet 4.6 support up to 300k output tokens with the output-300k-2026-03-24 beta header.
5454* **Reliable knowledge cutoff:** The date through which the model’s knowledge is most extensive and reliable. Training data cutoff (under Additional details) is the broader range of data used. See Anthropic’s Transparency Hub for details.
5555* **Retirement:** Anthropic’s commitment for Anthropic-operated platforms (Claude API, Claude Platform on AWS, Microsoft Foundry). Amazon Bedrock and Google Cloud set their own dates.
5656* **Claude API alias:** For models before the 4.6 generation, the alias is a convenience pointer that resolves to the dated ID. Dateless IDs are their own pinned snapshot; the alias row repeats them.
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6262See [Model IDs and versioning](https://platform.claude.com/docs/en/about-claude/models/model-ids-and-versions) and [Pricing](https://platform.claude.com/docs/en/about-claude/pricing).
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64Legacy models (still available): [Claude Fable 5](https://platform.claude.com/docs/en/models/fable-5/overview), [Claude Opus 5](https://platform.claude.com/docs/en/models/opus-5/overview), [Claude Opus 4.8](https://platform.claude.com/docs/en/models/opus-4-8/overview), [Claude Opus 4.7](https://platform.claude.com/docs/en/models/opus-4-7/overview), [Claude Opus 4.6](https://platform.claude.com/docs/en/models/opus-4-6/overview), [Claude Opus 4.5](https://platform.claude.com/docs/en/models/opus-4-5/overview), [Claude Sonnet 4.6](https://platform.claude.com/docs/en/models/sonnet-4-6/overview), [Claude Sonnet 4.5](https://platform.claude.com/docs/en/models/sonnet-4-5/overview).
64Legacy models (still available): [Claude Fable 5](https://platform.claude.com/docs/en/models/fable-5/overview), [Claude Opus 5](https://platform.claude.com/docs/en/models/opus-5/overview), [Claude Opus 4.8](https://platform.claude.com/docs/en/models/opus-4-8/overview), [Claude Opus 4.7](https://platform.claude.com/docs/en/models/opus-4-7/overview), [Claude Opus 4.6](https://platform.claude.com/docs/en/models/opus-4-6/overview), [Claude Opus 4.5](https://platform.claude.com/docs/en/models/opus-4-5/overview), [Claude Sonnet 5](https://platform.claude.com/docs/en/models/sonnet-5/overview), [Claude Sonnet 4.6](https://platform.claude.com/docs/en/models/sonnet-4-6/overview), [Claude Sonnet 4.5](https://platform.claude.com/docs/en/models/sonnet-4-5/overview).
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6666Once you've picked a model, [learn how to make your first API call](https://platform.claude.com/docs/en/get-started). To understand how model IDs, aliases, and snapshots work, see [Model IDs and versioning](https://platform.claude.com/docs/en/about-claude/models/model-ids-and-versions); for the reliable-knowledge and training-data cutoffs behind each model, see [Anthropic's Transparency Hub](https://www.anthropic.com/transparency).
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