Model comparison

Claude Fable 5.1 vs Kimi K3

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 59.5 on the Noometry Index. Kimi K3 costs 3.3× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

Last verified . 43 shared benchmarks.

Claude Fable 5.1 Anthropic

69.0

Rank #2 Confirmed

Kimi K3 Moonshot AI

59.5

Rank #15 Confirmed

Summary

  • They share 43 benchmarks with published results for both. Claude Fable 5.1 scores higher in 10 categories and Kimi K3 in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in multimodal, where Claude Fable 5.1 leads 53.9 to 37.8.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 87.8% for Claude Fable 5.1 and 39% for Kimi K3.
  • Kimi K3 is cheaper at $3 / $15 per million input/output tokens, against $10 / $50 for Claude Fable 5.1.
  • Kimi K3 accepts more context: 1.05M tokens versus 1M.
  • Kimi K3 has downloadable open weights; the other is API-only.

Side by side

Claude Fable 5.1 and Kimi K3 specifications
Claude Fable 5.1Kimi K3
ProviderAnthropicMoonshot AI
Noometry Index69.059.5
Released2026-09-012026-07-16
WeightsProprietaryOpen
Context window1M1.05M
Max output128K1.05M
Input $ / M tokens$10$3
Output $ / M tokens$50$15
Results tracked5253

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Category by category

Coding Claude Fable 5.1 leads

Claude Fable 5.1: 74.7 (#1), Kimi K3: 61.0 (#10)

Coding benchmarks
BenchmarkClaude Fable 5.1Kimi K3
FrontierCode50.9%44.2%
LMArena WebDev17441654
FrontierSWE56.3%25.9%
SciCode63.1%59.5%
WeirdML92.9%82.6%
LMArena Coding15281508
ALE-Bench2,1431,524
DeepSWE—68.5%
CursorBench51.8%—
GSO88.2%—
MirrorCode73.3%—

Agentic & Tool Use Claude Fable 5.1 leads

Claude Fable 5.1: 50.7 (#5), Kimi K3: 41.8 (#20)

Agentic & Tool Use benchmarks
BenchmarkClaude Fable 5.1Kimi K3
APEX-Agents68.6%50.6%
GDP.pdf29.6%19%
Vending-Bench 25,4225,165
Remote Labor Index17.9%—
τ²-bench Banking—37.1%
PostTrainBench—32%
GBAEval—48.3%

Reasoning Claude Fable 5.1 leads

Claude Fable 5.1: 76.7 (#7), Kimi K3: 63.0 (#17)

Reasoning benchmarks
BenchmarkClaude Fable 5.1Kimi K3
ARC-AGI-290%60.4%
NYT Connections (extended)90%93.6%
ARC-AGI-197.5%94.5%
CritPt31.1%23.4%
Chess Puzzles47%39%
LMArena Hard Prompts15261496
Mystery Game Puzzles58%26%
DTBench97.6%91.2%
LMCA65.5%52.7%
Epoch Capabilities Index164.7157.45
SimpleBench—60.7%
EBR-Bench57.1%—
Surface Evolver Bench—95%
ForecastBench—61.1

Math Claude Fable 5.1 leads

Claude Fable 5.1: 89.6 (#4), Kimi K3: 74.2 (#16)

Math benchmarks
BenchmarkClaude Fable 5.1Kimi K3
FrontierMath (Tiers 1-3)90.2%72.2%
FrontierMath Tier 487.8%39%
OTIS Mock AIME 2024-2025100%97.2%
ProofBench100%87%
LMArena Math15251491
MathArena Final-Answer Competitions—87.8%
FrontierMath Erdős0%—

Knowledge Claude Fable 5.1 leads

Claude Fable 5.1: 69.6 (#6), Kimi K3: 63.2 (#21)

Knowledge benchmarks
BenchmarkClaude Fable 5.1Kimi K3
SimpleQA Verified70.8%50.6%
LMArena Expert15351521
GPQA Diamond—93.1%
Humanity's Last Exam46.5%—

Multimodal Claude Fable 5.1 leads

Claude Fable 5.1: 53.9 (#4), Kimi K3: 37.8 (#70)

Multimodal benchmarks
BenchmarkClaude Fable 5.1Kimi K3
Blueprint-Bench 241.9%29.5%
Furniture Assembly70%34.2%
LMArena Vision1318—
LMArena Document1513—

Multilingual Claude Fable 5.1 leads

Claude Fable 5.1: 59.1 (#3), Kimi K3: 56.3 (#21)

Multilingual benchmarks
BenchmarkClaude Fable 5.1Kimi K3
LMArena Non-English15071466
LMArena Chinese15861529
LMArena French15251491
LMArena German15001488
LMArena Japanese15431487
LMArena Korean15341458
LMArena Russian15211482
LMArena Spanish15161472

Instruction Following Claude Fable 5.1 leads

Claude Fable 5.1: 79.2 (#6), Kimi K3: 77.7 (#14)

Instruction Following benchmarks
BenchmarkClaude Fable 5.1Kimi K3
LMArena Instruction Following15171483

Long Context Too close to call

Claude Fable 5.1: 46.7 (#20), Kimi K3: 45.8 (#29)

Long Context benchmarks
BenchmarkClaude Fable 5.1Kimi K3
LMArena Longer Query15221494

Writing & Preference Claude Fable 5.1 leads

Claude Fable 5.1: 79.2 (#2), Kimi K3: 76.6 (#4)

Writing & Preference benchmarks
BenchmarkClaude Fable 5.1Kimi K3
LMArena Text15101476
LMArena Creative Writing15071454
EQ-Bench Creative Writing21622082
LMArena Multi-Turn14921488
EQ-Bench 4—1339

Frequently asked questions

Is Claude Fable 5.1 better than Kimi K3?

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 59.5 on the Noometry Index. Kimi K3 costs 3.3× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

Which is cheaper, Claude Fable 5.1 or Kimi K3?

Kimi K3 is cheaper. It lists at $3 per million input tokens and $15 per million output tokens; Claude Fable 5.1 lists at $10 and $50.

Is Claude Fable 5.1 or Kimi K3 better for coding?

Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 61.0 in the Noometry coding category.

Which has the bigger context window?

Kimi K3 does, with 1.05M tokens against 1M.

How many benchmarks do Claude Fable 5.1 and Kimi K3 share?

43 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and Kimi K3 has 53.

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