Anthropic: Claude Opus 4.1 vs Anthropic: Claude Fable 5.1 — pricing compared

Side-by-side API pricing for Anthropic: Claude Opus 4.1 and Anthropic: Claude Fable 5.1, normalized to $/1M tokens from the live OpenRouter feed.

Token Price Index › Browse › Anthropic: Claude Opus 4.1 vs Anthropic: Claude Fable 5.1

On blended cost, Anthropic: Claude Fable 5.1 ($20.00/M) is about 33% cheaper than Anthropic: Claude Opus 4.1 ($30.00/M) per 1M tokens. Anthropic: Claude Fable 5.1 wins on input price, Anthropic: Claude Fable 5.1 on output, and Anthropic: Claude Fable 5.1 has the larger context window.

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ModelContextInput $/MOutput $/MBlended $/M
Anthropic: Claude Opus 4.1visioncache
anthropic
200,000$15.00/M$75.00/M$30.00/M
Anthropic: Claude Fable 5.1visioncache
anthropic
1,000,000$10.00/M$50.00/M$20.00/M

Frequently asked questions

Is Anthropic: Claude Opus 4.1 or Anthropic: Claude Fable 5.1 cheaper?
On a blended basis Anthropic: Claude Fable 5.1 is cheaper at $20.00/M per 1M tokens versus $30.00/M for Anthropic: Claude Opus 4.1 — about 33% less. Blended weights input 3:1 over output.
Anthropic: Claude Opus 4.1 vs Anthropic: Claude Fable 5.1: input token cost?
Anthropic: Claude Opus 4.1 charges $15.00/M per 1M input tokens; Anthropic: Claude Fable 5.1 charges $10.00/M. Anthropic: Claude Fable 5.1 is cheaper on input.
Anthropic: Claude Opus 4.1 vs Anthropic: Claude Fable 5.1: output token cost?
Anthropic: Claude Opus 4.1 charges $75.00/M per 1M output tokens; Anthropic: Claude Fable 5.1 charges $50.00/M. Anthropic: Claude Fable 5.1 is cheaper on output.
Which has the larger context window, Anthropic: Claude Opus 4.1 or Anthropic: Claude Fable 5.1?
Anthropic: Claude Opus 4.1 supports 200,000 tokens and Anthropic: Claude Fable 5.1 supports 1,000,000 tokens, so Anthropic: Claude Fable 5.1 handles longer inputs in a single call.
How do I track Anthropic: Claude Opus 4.1 and Anthropic: Claude Fable 5.1 price changes?
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Data: OpenRouter public model API, normalized to $/1M tokens. Blended = (3×input + output)/4. Generated 19 Oct 2026 22:00 UTC. Prices change often — confirm on the provider before committing spend.