Model comparison

Claude Fable 5.1 vs GPT-4.1

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 35.9 on the Noometry Index. GPT-4.1 costs 5.7× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

Last verified . 31 shared benchmarks.

Claude Fable 5.1 Anthropic

69.0

Rank #2 Confirmed

GPT-4.1 OpenAI

35.9

Rank #219 Confirmed

Summary

  • They share 31 benchmarks with published results for both. Claude Fable 5.1 scores higher in 10 categories and GPT-4.1 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 22.3.
  • The biggest single-benchmark swing is ARC-AGI-1: 97.5% for Claude Fable 5.1 and 5.5% for GPT-4.1.
  • GPT-4.1 is cheaper at $2 / $8 per million input/output tokens, against $10 / $50 for Claude Fable 5.1.
  • GPT-4.1 accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Fable 5.1 and GPT-4.1 specifications
Claude Fable 5.1GPT-4.1
ProviderAnthropicOpenAI
Noometry Index69.035.9
Released2026-09-012025-04-14
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K33K
Input $ / M tokens$10$2
Output $ / M tokens$50$8
Results tracked5252

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Category by category

Coding Claude Fable 5.1 leads

Claude Fable 5.1: 74.7 (#1), GPT-4.1: 34.4 (#238)

Coding benchmarks
BenchmarkClaude Fable 5.1GPT-4.1
WeirdML92.9%39%
LMArena Coding15281391
ALE-Bench2,143558.1
SWE-bench Verified—48.5%
FrontierCode50.9%—
SWE-bench Verified (bash only)—39.6%
Aider Polyglot—52.4%
CursorBench51.8%—
LMArena WebDev1744—
FrontierSWE56.3%—
SciCode63.1%—
GSO88.2%—
MirrorCode73.3%—
CadEval—42%

Agentic & Tool Use Claude Fable 5.1 leads

Claude Fable 5.1: 50.7 (#5), GPT-4.1: 34.7 (#43)

Agentic & Tool Use benchmarks
BenchmarkClaude Fable 5.1GPT-4.1
APEX-Agents68.6%—
Berkeley Function Calling Leaderboard—54%
Remote Labor Index17.9%—
GDP.pdf29.6%—
Vending-Bench 25,422—

Reasoning Claude Fable 5.1 leads

Claude Fable 5.1: 76.7 (#7), GPT-4.1: 11.7 (#339)

Reasoning benchmarks
BenchmarkClaude Fable 5.1GPT-4.1
ARC-AGI-290%0.4%
ARC-AGI-197.5%5.5%
Chess Puzzles47%6%
LMArena Hard Prompts15261384
DTBench97.6%68.3%
LMCA65.5%25.6%
Epoch Capabilities Index164.7136.78
SimpleBench—27%
Kagi LLM Benchmark—52.3%
NYT Connections (extended)90%—
CritPt31.1%—
EnigmaEval—2.2%
EBR-Bench57.1%—
Mystery Game Puzzles58%—
ForecastBench—61.5

Math Claude Fable 5.1 leads

Claude Fable 5.1: 89.6 (#4), GPT-4.1: 22.3 (#280)

Knowledge Claude Fable 5.1 leads

Claude Fable 5.1: 69.6 (#6), GPT-4.1: 37.1 (#160)

Knowledge benchmarks
BenchmarkClaude Fable 5.1GPT-4.1
Humanity's Last Exam46.5%5.4%
SimpleQA Verified70.8%31.1%
LMArena Expert15351364
GPQA Diamond—66.9%
MMLU-Pro—81.1%
Vectara Hallucination Rate—5.6%
GPQA (HELM)—65.9%

Multimodal Claude Fable 5.1 leads

Claude Fable 5.1: 53.9 (#4), GPT-4.1: 38.2 (#67)

Multimodal benchmarks
BenchmarkClaude Fable 5.1GPT-4.1
LMArena Vision13181211
GeoBench—72%
Blueprint-Bench 241.9%—
Furniture Assembly70%—
LMArena Document1513—

Multilingual Claude Fable 5.1 leads

Claude Fable 5.1: 59.1 (#3), GPT-4.1: 49.4 (#133)

Multilingual benchmarks
BenchmarkClaude Fable 5.1GPT-4.1
LMArena Non-English15071370
LMArena Chinese15861382
LMArena French15251382
LMArena German15001381
LMArena Japanese15431319
LMArena Korean15341339
LMArena Russian15211377
LMArena Spanish15161376

Instruction Following Claude Fable 5.1 leads

Claude Fable 5.1: 79.2 (#6), GPT-4.1: 71.3 (#153)

Instruction Following benchmarks
BenchmarkClaude Fable 5.1GPT-4.1
LMArena Instruction Following15171367
IFEval—83.8%

Long Context Claude Fable 5.1 leads

Claude Fable 5.1: 46.7 (#20), GPT-4.1: 40.0 (#163)

Long Context benchmarks
BenchmarkClaude Fable 5.1GPT-4.1
LMArena Longer Query15221385
Fiction.LiveBench—63.9%

Writing & Preference Claude Fable 5.1 leads

Claude Fable 5.1: 79.2 (#2), GPT-4.1: 57.6 (#125)

Writing & Preference benchmarks
BenchmarkClaude Fable 5.1GPT-4.1
LMArena Text15101383
LMArena Creative Writing15071363
EQ-Bench Creative Writing21621420
LMArena Multi-Turn14921398
WildBench—85.4%

Frequently asked questions

Is Claude Fable 5.1 better than GPT-4.1?

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 35.9 on the Noometry Index. GPT-4.1 costs 5.7× 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-4.1?

GPT-4.1 is cheaper. It lists at $2 per million input tokens and $8 per million output tokens; Claude Fable 5.1 lists at $10 and $50.

Is Claude Fable 5.1 or GPT-4.1 better for coding?

Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 34.4 in the Noometry coding category.

Which has the bigger context window?

GPT-4.1 does, with 1.05M tokens against 1M.

How many benchmarks do Claude Fable 5.1 and GPT-4.1 share?

31 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and GPT-4.1 has 52.

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