Noometry

Model comparison

Claude Fable 5 vs Claude Opus 4

Claude Fable 5 is the stronger model overall, scoring 66.8 to 43.1 on the Noometry Index.

Last verified . 33 shared benchmarks.

Claude Fable 5 Anthropic

66.8

Rank #5 Confirmed

Claude Opus 4 Anthropic

43.1

Rank #100 Confirmed

Summary

  • They share 33 benchmarks with published results for both. Claude Fable 5 scores higher in 10 categories and Claude Opus 4 in 0 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Fable 5 leads 76.8 to 27.3.
  • The biggest single-benchmark swing is ARC-AGI-2: 89.2% for Claude Fable 5 and 8.6% for Claude Opus 4.
  • Claude Fable 5 is cheaper at $10 / $50 per million input/output tokens, against $15 / $75 for Claude Opus 4.
  • Claude Fable 5 accepts more context: 1M tokens versus 200K.

Side by side

Claude Fable 5Claude Opus 4
ProviderAnthropicAnthropic
Noometry Index66.843.1
Released2026-06-072025-05-22
WeightsProprietaryProprietary
Context window1M200K
Max output128K32K
Input $ / M tokens$10$15
Output $ / M tokens$50$75
Results tracked6256

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Category by category

Coding Claude Fable 5 leads

Claude Fable 5: 70.6 (#4), Claude Opus 4: 47.2 (#62)

BenchmarkClaude Fable 5Claude Opus 4
GSO78.4%6.9%
WeirdML91.9%43.7%
LMArena Coding15191442
SWE-bench Verified—70.7%
DeepSWE69.9%—
FrontierCode53.5%—
SWE-bench Verified (bash only)—67.6%
Aider Polyglot—72%
LMArena WebDev1625—
FrontierSWE47%—
SciCode61%—
MirrorCode63.9%—
ALE-Bench2,041—
AlgoTune—1.33

Agentic & Tool Use Claude Fable 5 leads

Claude Fable 5: 54.0 (#2), Claude Opus 4: 34.8 (#42)

BenchmarkClaude Fable 5Claude Opus 4
LMArena Search12301127
APEX-Agents63.6%—
Remote Labor Index16.1%—
τ²-bench Banking39.7%—
Cybench—38%
DeepResearch Bench—46.8%
PostTrainBench41.8%—
GBAEval74.5%—
GDP.pdf30%—
METR Time Horizons—63.9%
Vending-Bench 25,680—

Reasoning Claude Fable 5 leads

Claude Fable 5: 76.8 (#6), Claude Opus 4: 27.3 (#121)

BenchmarkClaude Fable 5Claude Opus 4
ARC-AGI-289.2%8.6%
SimpleBench81.9%58.8%
Kagi LLM Benchmark91.4%74.3%
ARC-AGI-198.5%35.7%
CritPt28.6%0.3%
EnigmaEval39.3%5.6%
LMArena Hard Prompts15081399
DTBench98.4%81.6%
LMCA61.1%37.4%
Epoch Capabilities Index162.06142.67
NYT Connections (extended)92.7%—
Chess Puzzles41%—
EBR-Bench39.5%—
Mystery Game Puzzles52%—
Surface Evolver Bench95%—
Bench to the Future 30.13—
ForecastBench—61.1

Math Claude Fable 5 leads

Claude Fable 5: 88.5 (#5), Claude Opus 4: 42.0 (#86)

BenchmarkClaude Fable 5Claude Opus 4
OTIS Mock AIME 2024-2025100%64.4%
LMArena Math15191390
FrontierMath (Tiers 1-3)87%—
FrontierMath Tier 490.2%—
ProofBench95%—
Omni-MATH—61.6%
MATH Level 5—85%
FrontierMath (Feb 2025 set)—4.5%
FrontierMath Erdős0%—
FrontierMath Tier 4 (v1)—4.2%

Knowledge Claude Fable 5 leads

Claude Fable 5: 62.2 (#25), Claude Opus 4: 44.0 (#88)

BenchmarkClaude Fable 5Claude Opus 4
GPQA Diamond85.9%76.3%
LMArena Expert15341386
Humanity's Last Exam—10.7%
SimpleQA Verified70.7%—
MMLU-Pro—87.5%
Confabulations—15.9%
Vectara Hallucination Rate—12%
GPQA (HELM)—70.8%

Multimodal Claude Fable 5 leads

Claude Fable 5: 45.3 (#17), Claude Opus 4: 31.5 (#106)

BenchmarkClaude Fable 5Claude Opus 4
LMArena Vision13241192
GeoBench—49%
VPCT—38%
Blueprint-Bench 238.6%—
Furniture Assembly35.8%—
LMArena Document1496—

Multilingual Claude Fable 5 leads

Claude Fable 5: 57.3 (#9), Claude Opus 4: 48.8 (#138)

BenchmarkClaude Fable 5Claude Opus 4
LMArena Non-English14811362
LMArena Chinese15431386
LMArena French15051372
LMArena German14861391
LMArena Japanese15061331
LMArena Korean14881321
LMArena Russian15041392
LMArena Spanish14981389

Instruction Following Claude Fable 5 leads

Claude Fable 5: 78.6 (#8), Claude Opus 4: 77.1 (#28)

BenchmarkClaude Fable 5Claude Opus 4
LMArena Instruction Following15021406
IFEval—91.8%

Long Context Claude Fable 5 leads

Claude Fable 5: 46.3 (#23), Claude Opus 4: 39.6 (#172)

BenchmarkClaude Fable 5Claude Opus 4
LMArena Longer Query15091422
Fiction.LiveBench—61.1%

Writing & Preference Claude Fable 5 leads

Claude Fable 5: 75.9 (#5), Claude Opus 4: 61.2 (#89)

BenchmarkClaude Fable 5Claude Opus 4
LMArena Text14911377
LMArena Creative Writing14941387
EQ-Bench Creative Writing19431580
LMArena Multi-Turn15041396
Short-Story Creative Writing—83.6%
WildBench—85.2%
EQ-Bench 41340—

Frequently asked questions

Is Claude Fable 5 better than Claude Opus 4?

Claude Fable 5 is the stronger model overall, scoring 66.8 to 43.1 on the Noometry Index.

Which is cheaper, Claude Fable 5 or Claude Opus 4?

Claude Fable 5 is cheaper. It lists at $10 per million input tokens and $50 per million output tokens; Claude Opus 4 lists at $15 and $75.

Is Claude Fable 5 or Claude Opus 4 better for coding?

Claude Fable 5 scores higher on coding benchmarks: 70.6 versus 47.2 in the Noometry coding category.

Which has the bigger context window?

Claude Fable 5 does, with 1M tokens against 200K.

How many benchmarks do Claude Fable 5 and Claude Opus 4 share?

33 benchmarks have published results for both models. Claude Fable 5 has 62 scored results on Noometry and Claude Opus 4 has 56.

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