> For the complete documentation index, see [llms.txt](https://docs.flora.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.flora.ai/models/text-models/claude-fable-5-by-anthropic.md).

# Claude Fable 5 (by Anthropic)

### Overview

Anthropic's model for the most demanding reasoning and long-horizon agentic work. **Claude Fable 5.1** is the current successor, priced the same, with always-on adaptive thinking.

***

### Quick facts

* **Modes:** Text → Text · Image → Text · Video → Text
* **Default output / size:** Text responses (token-limited)
* **Thinking:** Adaptive (always on for 5.1)

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### What it's great for

* Long-running agent loops.
* Highest-stakes analysis and planning.
* Tasks that need extended thinking time.

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### Parameters

| Control     | Type | Default | Notes                                   |
| ----------- | ---- | ------- | --------------------------------------- |
| Prompt      | Text | —       | Natural-language instruction (required) |
| Input Texts | List | —       | Optional supporting documents           |

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### Modes

| Mode         | Estimated time | Required inputs | Typical use                   |
| ------------ | -------------: | --------------- | ----------------------------- |
| Text → Text  |          \~25s | Prompt          | Deep reasoning & agentic work |
| Image → Text |          \~25s | Images, Prompt  | Complex visual analysis       |
| Video → Text |          \~25s | Videos, Prompt  | Long-form video understanding |

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