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Head-to-head comparison

Claude Fable 5 vs Claude Fable 5.1

Claude Fable 5 (Anthropic) and Claude Fable 5.1 (Anthropic) compared on the ModelCap Index, API price, context window, provider availability, weight access and every public benchmark board they share. Figures are the same ones shown on the live rankings; nothing here is a hidden score.

Snapshot as of 3 September 2026

As of 3 September 2026, Claude Fable 5 holds the stronger ModelCap Index position (#1 vs #2).

Which should you choose?

Choose Claude Fable 5 if…

  • you want the stronger overall ModelCap Index position — #1 against #2 (85.3 vs 84.1 points).
  • you want provider choice — 5 listed API providers against 4.

Choose Claude Fable 5.1 if…

  • ARC-AGI-2 is your yardstick — 90.0% against 89.2%.
  • AA Intelligence Index is your yardstick — 65.7 against 62.1.
  • AA Terminal-Bench 2.1 is your yardstick — 91.4% against 84.6%.
  • AA Humanity's Last Exam is your yardstick — 59.1% against 55.5%.
  • you want the more recently listed model — Claude Fable 5.1 was listed 1 September 2026, Claude Fable 5 9 June 2026.

Claude Fable 5 vs Claude Fable 5.1: specs, pricing and context

Specification comparison of Claude Fable 5 and Claude Fable 5.1
FieldClaude Fable 5AnthropicClaude Fable 5.1Anthropic
ModelCap Index position#1#2
Index score85.384.1
EvidenceMeasuredMeasured
Input price / 1M tokens$10.00$10.00
Output price / 1M tokens$50.00$50.00
Context window1M tokens1M tokens
Max output tokens128K128K
API providers listed54
Weight accessAPI onlyAPI only
Input modalitiesText, Image, FileText, Image, File
First listed9 June 20261 September 2026
PublisherAnthropicAnthropic

Evidence: 6 public benchmark observations across 6 boards · 2 public benchmark observations across 2 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Claude Fable 5 vs Claude Fable 5.1

Public benchmark boards where Claude Fable 5 or Claude Fable 5.1 has a published result
BoardClaude Fable 5Claude Fable 5.1Leads
Arena codingArena (LMArena)15511544–1559—Only one result
LMArena AgentLMArena10.6%9.0%–12.1%High—Only one result
ARC-AGI-2ARC Prize Foundation89.2%Max90.0%MaxClaude Fable 5.1
AA Intelligence IndexArtificial Analysis62.1intelligence-index65.7intelligence-indexClaude Fable 5.1
AA Terminal-Bench 2.1Artificial Analysis84.6%terminal-bench-2.191.4%terminal-bench-2.1Claude Fable 5.1
AA τ²-Bench TelecomArtificial Analysis98.5%tau2-bench-telecom—Only one result
AA Humanity's Last ExamArtificial Analysis55.5%humanitys-last-exam59.1%humanitys-last-examClaude Fable 5.1
Terminal-Bench 4.0Terminal-Bench (Laude Institute)44.6%40.7%–48.4%Claude Code · Max—Only one result
WildClawBench OpenClawWildClawBench62.0—Only one result

Scores are the sources' own published figures for each model's best evaluated configuration; ModelCap never re-runs a benchmark.

Want a different pairing? Open the interactive comparison tool to swap either model for any current ranked language model.

Claude Fable 5 vs Claude Fable 5.1: common questions

Is Claude Fable 5 better than Claude Fable 5.1?

Claude Fable 5 ranks higher on the ModelCap Index as of 3 September 2026: #1 against #2. That is a capability ranking built from public benchmark evidence with published uncertainty; whether it is "better" for you also depends on price, context and where you can run it.

Is Claude Fable 5 cheaper than Claude Fable 5.1?

Both list the same output price, $50.00/1M tokens, with input at $10.00/1M and $10.00/1M respectively.

Which has the bigger context window, Claude Fable 5 or Claude Fable 5.1?

Both publish a 1M-token context window.

Which is better for coding, Claude Fable 5 or Claude Fable 5.1?

AA Terminal-Bench 2.1: Claude Fable 5 84.6%, Claude Fable 5.1 91.4% — Claude Fable 5.1 leads.

Are Claude Fable 5 and Claude Fable 5.1 open-weight models?

Claude Fable 5: API only. Claude Fable 5.1: API only. Open weights mean the checkpoint can be downloaded and self-hosted under its licence; API-only models are available solely through hosted endpoints.

Where can I run Claude Fable 5 and Claude Fable 5.1?

ModelCap currently lists 5 API providers for Claude Fable 5 and 4 for Claude Fable 5.1, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Claude Fable 5 vs Claude Fable 5.1 comparison?

Every figure comes from the sealed ModelCap dataset published 3 September 2026; the page re-renders within a minute of each data refresh, and the ModelCap Index positions are the same ones shown on the live rankings.

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