Noometry

Model comparison

Claude Fable 5.1 vs GPT-4o mini

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 25.5 on the Noometry Index. GPT-4o mini costs 76× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

Last verified . 29 shared benchmarks.

Claude Fable 5.1 Anthropic

69.0

Rank #2 Confirmed

GPT-4o mini OpenAI

25.5

Rank #343 Confirmed

Summary

  • They share 29 benchmarks with published results for both. Claude Fable 5.1 scores higher in 10 categories and GPT-4o mini in 0 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Fable 5.1 leads 89.6 to 10.4.
  • The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Fable 5.1 and 6.9% for GPT-4o mini.
  • GPT-4o mini is cheaper at $0.15 / $0.60 per million input/output tokens, against $10 / $50 for Claude Fable 5.1.
  • Claude Fable 5.1 accepts more context: 1M tokens versus 128K.

Side by side

Claude Fable 5.1GPT-4o mini
ProviderAnthropicOpenAI
Noometry Index69.025.5
Released2026-09-012024-07-18
WeightsProprietaryProprietary
Context window1M128K
Max output128K16K
Input $ / M tokens$10$0.15
Output $ / M tokens$50$0.60
Results tracked5260

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Category by category

Coding Claude Fable 5.1 leads

Claude Fable 5.1: 74.7 (#1), GPT-4o mini: 22.0 (#335)

BenchmarkClaude Fable 5.1GPT-4o mini
WeirdML92.9%11.8%
LMArena Coding15281290
FrontierCode50.9%—
Aider Polyglot—3.6%
CursorBench51.8%—
LMArena WebDev1744—
FrontierSWE56.3%—
SciCode63.1%—
GSO88.2%—
BigCodeBench Instruct—46.1%
LiveBench Coding—43.1%
MirrorCode73.3%—
BigCodeBench Complete—57.4%
ALE-Bench2,143—
HumanEval+—83.5%
MBPP+—72.2%

Agentic & Tool Use Claude Fable 5.1 leads

Claude Fable 5.1: 50.7 (#5), GPT-4o mini: 27.5 (#101)

BenchmarkClaude Fable 5.1GPT-4o mini
APEX-Agents68.6%—
Remote Labor Index17.9%—
BALROG—17.4%
GDP.pdf29.6%—
Vending-Bench 25,422—

Reasoning Claude Fable 5.1 leads

Claude Fable 5.1: 76.7 (#7), GPT-4o mini: 8.7 (#347)

BenchmarkClaude Fable 5.1GPT-4o mini
ARC-AGI-290%0%
Chess Puzzles47%0%
LMArena Hard Prompts15261267
Mystery Game Puzzles58%12%
DTBench97.6%54.4%
LMCA65.5%10.4%
Epoch Capabilities Index164.7126.56
SimpleBench—10.7%
Kagi LLM Benchmark—28.8%
NYT Connections (extended)90%—
ARC-AGI-197.5%—
CritPt31.1%—
EBR-Bench57.1%—
LiveBench Reasoning—32.8%
LiveBench Data Analysis—50%
LiveBench—41.3%
PIQA—88.7%

Math Claude Fable 5.1 leads

Claude Fable 5.1: 89.6 (#4), GPT-4o mini: 10.4 (#314)

BenchmarkClaude Fable 5.1GPT-4o mini
FrontierMath (Tiers 1-3)90.2%0.7%
OTIS Mock AIME 2024-2025100%6.9%
LMArena Math15251267
FrontierMath Tier 487.8%—
ProofBench100%—
Omni-MATH—28%
LiveBench Math—36.3%
MATH Level 5—52.6%
FrontierMath Erdős0%—
GSM8K—91.3%

Knowledge Claude Fable 5.1 leads

Claude Fable 5.1: 69.6 (#6), GPT-4o mini: 17.7 (#284)

BenchmarkClaude Fable 5.1GPT-4o mini
SimpleQA Verified70.8%8.3%
LMArena Expert15351235
GPQA Diamond—37.7%
Humanity's Last Exam46.5%—
MMLU-Pro—60.3%
Confabulations—37.2%
GPQA (HELM)—36.8%
BoolQ—88.7%
MMLU—81.8%

Multimodal Claude Fable 5.1 leads

Claude Fable 5.1: 53.9 (#4), GPT-4o mini: 25.9 (#122)

BenchmarkClaude Fable 5.1GPT-4o mini
LMArena Vision13181066
Video-MME—64.8%
GeoBench—64%
VPCT—34%
Blueprint-Bench 241.9%—
Furniture Assembly70%—
LMArena Document1513—

Multilingual Claude Fable 5.1 leads

Claude Fable 5.1: 59.1 (#3), GPT-4o mini: 42.0 (#199)

BenchmarkClaude Fable 5.1GPT-4o mini
LMArena Non-English15071266
LMArena Chinese15861265
LMArena French15251297
LMArena German15001272
LMArena Japanese15431216
LMArena Korean15341195
LMArena Russian15211275
LMArena Spanish15161276

Instruction Following Claude Fable 5.1 leads

Claude Fable 5.1: 79.2 (#6), GPT-4o mini: 61.9 (#239)

BenchmarkClaude Fable 5.1GPT-4o mini
LMArena Instruction Following15171258
LiveBench Instruction Following—56.8%
IFEval—78.2%

Long Context Claude Fable 5.1 leads

Claude Fable 5.1: 46.7 (#20), GPT-4o mini: 39.1 (#186)

BenchmarkClaude Fable 5.1GPT-4o mini
LMArena Longer Query15221289

Writing & Preference Claude Fable 5.1 leads

Claude Fable 5.1: 79.2 (#2), GPT-4o mini: 39.5 (#248)

BenchmarkClaude Fable 5.1GPT-4o mini
LMArena Text15101286
LMArena Creative Writing15071268
EQ-Bench Creative Writing2162873
LMArena Multi-Turn14921285
Short-Story Creative Writing—67.2%
WildBench—79.1%
LiveBench Language—28.6%

Frequently asked questions

Is Claude Fable 5.1 better than GPT-4o mini?

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 25.5 on the Noometry Index. GPT-4o mini costs 76× 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 GPT-4o mini?

GPT-4o mini is cheaper. It lists at $0.15 per million input tokens and $0.60 per million output tokens; Claude Fable 5.1 lists at $10 and $50.

Is Claude Fable 5.1 or GPT-4o mini better for coding?

Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 22.0 in the Noometry coding category.

Which has the bigger context window?

Claude Fable 5.1 does, with 1M tokens against 128K.

How many benchmarks do Claude Fable 5.1 and GPT-4o mini share?

29 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and GPT-4o mini has 60.

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