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Head-to-head comparison

Claude Fable 5.1 vs Inkling

Claude Fable 5.1 (Anthropic) and Inkling (Thinking Machines) 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 5.1 holds the stronger ModelCap Index position (#2 vs #27); Inkling is 12.3× cheaper per output token ($4.05/1M vs $50.00/1M); and Inkling ships open weights.

Which should you choose?

Choose Claude Fable 5.1 if…

  • you want the stronger overall ModelCap Index position — #2 against #27 (84.1 vs 63.5 points).
  • you want provider choice — 4 listed API providers against 3.
  • ARC-AGI-2 is your yardstick — 90.0% against 36.5%.
  • AA Intelligence Index is your yardstick — 65.7 against 42.3.
  • AA Terminal-Bench 2.1 is your yardstick — 91.4% against 55.1%.
  • AA Humanity's Last Exam is your yardstick — 59.1% against 31.9%.
  • you want the more recently listed model — Claude Fable 5.1 was listed 1 September 2026, Inkling 17 July 2026.

Choose Inkling if…

  • API cost matters — $4.05/1M output tokens against $50.00/1M, about 12.3× cheaper.
  • your workload is prompt-heavy — input tokens cost $1.00/1M against $10.00/1M.
  • you want to self-host: Inkling ships open weights while Claude Fable 5.1 is api only.

Claude Fable 5.1 vs Inkling: specs, pricing and context

Specification comparison of Claude Fable 5.1 and Inkling
FieldClaude Fable 5.1AnthropicInklingThinking Machines
ModelCap Index position#2#27
Index score84.163.5
EvidenceMeasuredMeasured
Input price / 1M tokens$10.00$1.00
Output price / 1M tokens$50.00$4.05
Context window1M tokens1M tokens
Max output tokens128K472K
API providers listed43
Weight accessAPI onlyOpen weights
Input modalitiesText, Image, FileText, Image, Audio
First listed1 September 202617 July 2026
PublisherAnthropicThinking Machines

Evidence: 2 public benchmark observations across 2 boards · 5 public benchmark observations across 5 boards. Prices are the lowest listed API offer per million tokens observed on the OpenRouter catalogue.

Benchmark scores: Claude Fable 5.1 vs Inkling

Public benchmark boards where Claude Fable 5.1 or Inkling has a published result
BoardClaude Fable 5.1InklingLeads
Arena codingArena (LMArena)—14901482–1498Only one result
LMArena AgentLMArena—-7.0%-8.1%–-5.9%Only one result
ARC-AGI-2ARC Prize Foundation90.0%Max36.5%Claude Fable 5.1
AA Intelligence IndexArtificial Analysis65.7intelligence-index42.3intelligence-indexClaude Fable 5.1
AA Terminal-Bench 2.1Artificial Analysis91.4%terminal-bench-2.155.1%terminal-bench-2.1Claude Fable 5.1
AA Humanity's Last ExamArtificial Analysis59.1%humanitys-last-exam31.9%humanitys-last-examClaude Fable 5.1

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 5.1 vs Inkling: common questions

Is Claude Fable 5.1 better than Inkling?

Claude Fable 5.1 ranks higher on the ModelCap Index as of 3 September 2026: #2 against #27. 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 5.1 cheaper than Inkling?

Inkling is cheaper on output tokens: $4.05/1M against $50.00/1M. Input tokens are $10.00/1M for Claude Fable 5.1 and $1.00/1M for Inkling. Prices are the lowest listed API offer ModelCap observed, in USD per million tokens.

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

Both publish a 1M-token context window.

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

AA Terminal-Bench 2.1: Claude Fable 5.1 91.4%, Inkling 55.1% — Claude Fable 5.1 leads.

Are Claude Fable 5.1 and Inkling open-weight models?

Claude Fable 5.1: API only. Inkling: Open weights. 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 5.1 and Inkling?

ModelCap currently lists 4 API providers for Claude Fable 5.1 and 3 for Inkling, from the OpenRouter catalogue snapshot the site serves; each model page lists the providers and their prices.

How current is this Claude Fable 5.1 vs Inkling 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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