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Head-to-head comparison

Claude Fable 5.1 vs Kimi K3

Claude Fable 5.1 (Anthropic) and Kimi K3 (Moonshot AI) 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 #6); and Kimi K3 is 3.3× cheaper per output token ($15.00/1M vs $50.00/1M).

Which should you choose?

Choose Claude Fable 5.1 if…

  • you want the stronger overall ModelCap Index position — #2 against #6 (84.1 vs 81.4 points).
  • ARC-AGI-2 is your yardstick — 90.0% against 60.4%.
  • AA Intelligence Index is your yardstick — 65.7 against 59.7.
  • AA Terminal-Bench 2.1 is your yardstick — 91.4% against 85.0%.
  • AA Humanity's Last Exam is your yardstick — 59.1% against 46.9%.
  • you want the more recently listed model — Claude Fable 5.1 was listed 1 September 2026, Kimi K3 16 July 2026.

Choose Kimi K3 if…

  • API cost matters — $15.00/1M output tokens against $50.00/1M, about 3.3× cheaper.
  • your workload is prompt-heavy — input tokens cost $3.00/1M against $10.00/1M.
  • you want provider choice — 15 listed API providers against 4.

Claude Fable 5.1 vs Kimi K3: specs, pricing and context

Specification comparison of Claude Fable 5.1 and Kimi K3
FieldClaude Fable 5.1AnthropicKimi K3Moonshot AI
ModelCap Index position#2#6
Index score84.181.4
EvidenceMeasuredMeasured
Input price / 1M tokens$10.00$3.00
Output price / 1M tokens$50.00$15.00
Context window1M tokens1M tokens
Max output tokens128K944K
API providers listed415
Weight accessAPI onlyRestricted license
Input modalitiesText, Image, FileText, Image, Video
First listed1 September 202616 July 2026
PublisherAnthropicMoonshot AI

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

Benchmark scores: Claude Fable 5.1 vs Kimi K3

Public benchmark boards where Claude Fable 5.1 or Kimi K3 has a published result
BoardClaude Fable 5.1Kimi K3Leads
Arena codingArena (LMArena)—15421533–1551MaxOnly one result
LMArena AgentLMArena—8.7%8.1%–9.4%MaxOnly one result
ARC-AGI-2ARC Prize Foundation90.0%Max60.4%MaxClaude Fable 5.1
AA Intelligence IndexArtificial Analysis65.7intelligence-index59.7intelligence-indexClaude Fable 5.1
AA Terminal-Bench 2.1Artificial Analysis91.4%terminal-bench-2.185.0%terminal-bench-2.1Claude Fable 5.1
AA Humanity's Last ExamArtificial Analysis59.1%humanitys-last-exam46.9%humanitys-last-examClaude Fable 5.1
WildClawBench OpenClawWildClawBench—54.5Only 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 5.1 vs Kimi K3: common questions

Is Claude Fable 5.1 better than Kimi K3?

Claude Fable 5.1 ranks higher on the ModelCap Index as of 3 September 2026: #2 against #6. 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 Kimi K3?

Kimi K3 is cheaper on output tokens: $15.00/1M against $50.00/1M. Input tokens are $10.00/1M for Claude Fable 5.1 and $3.00/1M for Kimi K3. 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 Kimi K3?

Both publish a 1M-token context window.

Which is better for coding, Claude Fable 5.1 or Kimi K3?

AA Terminal-Bench 2.1: Claude Fable 5.1 91.4%, Kimi K3 85.0% — Claude Fable 5.1 leads.

Are Claude Fable 5.1 and Kimi K3 open-weight models?

Claude Fable 5.1: API only. Kimi K3: Restricted license. 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 Kimi K3?

ModelCap currently lists 4 API providers for Claude Fable 5.1 and 15 for Kimi K3, 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 Kimi K3 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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