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Model comparison

Claude Fable 5 vs Claude Fable 5.1

Compare Claude Fable 5 and Claude Fable 5.1 using the same provider-sourced text & reasoning rubric. No mystery score and no invented benchmark ranking.

Facts checked September 14, 2026

Estimate your cost

Set your usage. Your estimate updates as you type.

Example: 6,000 input tokens for 10 pages, plus a 500-token summary. Page lengths vary; adjust the numbers below.

One run sends your input to the model once and receives an answer. Tokens are pieces of text: input is what you send, output is the answer you receive.

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How this estimate works

Estimates exclude taxes, tools, cache storage/writes, free allowances and custom discounts. Image estimates cover output only, not prompt or reference-image charges. Quality modes differ by model. Unlisted settings are not treated as free.

Estimate your cost
ModelEstimated total (USD)
Claude Fable 5Anthropic$0.085
Claude Fable 5.1Anthropic$0.085

Quick take

Claude Fable 5

The original Fable model for complex coding and multi-step work, retained for existing integrations.

Best for

  • Complex coding
  • Migration evaluations

Watch out for

Check the newer Fable 5.1 and the mandatory retention requirements before starting a new project.

Claude Fable 5.1

Anthropic's frontier model for ambitious, long-running agentic and coding work, with strong vision and enterprise marketplace availability.

Best for

  • Long-running autonomous projects
  • Large codebase changes and review
  • Complex documents, diagrams, and enterprise workflows

Watch out for

Confirm whether the default 30-day retention, fallback safeguards, and selected cloud marketplace meet your governance requirements before adoption.

Compare the published facts

Claude Fable 5 vs Claude Fable 5.1

Values use each provider's own published units and limits. A blank means the provider did not publish a directly comparable value in the sources reviewed.

Text & reasoningClaude Fable 5Claude Fable 5.1
Context windowMaximum combined prompt and working context documented by the provider.1M tokens1M tokens
Maximum outputProvider-published response limit, where available.128K tokens128K tokens
Knowledge cutoffLatest reliable knowledge date explicitly published by the model provider. Search and connected tools can retrieve newer information but do not change the model's built-in cutoff.January 2026June 2026
Input priceCurrent standard list price per million input tokens unless noted.$10 / 1M$10 / 1M
Output priceCurrent standard list price per million output tokens unless noted.$50 / 1M$50 / 1M
InputsMedia types accepted by the listed model endpoint.Text, imageText, image, PDF
Tools & agentsSelected native tools and agent-building capabilities, not an exhaustive list.Tool use, agents, vision, coding workflowsTool use, agents, vision, coding workflows

How to choose

Compare the job, not the hype.

Start with the job you need to complete, then validate cost, access, and policy details on your exact provider route.

Claude Fable 5

Claude Fable 5 requires 30-day retention unless Anthropic authorizes an exception. API data is not used for training without express permission.

Claude Fable 5.1

Fable requires 30-day retention for safety monitoring by default. Anthropic says enterprise data is not used for training without explicit permission; eligible enterprises can use EFS/customer-controlled storage or temporary zero-retention arrangements.

Frequently asked questions

Claude Fable 5 vs Claude Fable 5.1 FAQ

What is the main difference between Claude Fable 5 and Claude Fable 5.1?

Claude Fable 5: The original Fable model for complex coding and multi-step work, retained for existing integrations. Claude Fable 5.1: Anthropic's frontier model for ambitious, long-running agentic and coding work, with strong vision and enterprise marketplace availability.

Should I choose Claude Fable 5 or Claude Fable 5.1?

Consider Claude Fable 5 when your priority is Complex coding. Consider Claude Fable 5.1 when your priority is Long-running autonomous projects. Test both with your own data and provider route before committing.

Is this Claude Fable 5 vs Claude Fable 5.1 comparison based on Cody benchmarks?

No. This comparison aligns provider-published facts for the Text & reasoning category. It does not claim a universal winner or combine incompatible third-party benchmark scores.