Noometry

Model comparison

Claude Fable 5.1 vs Gemini 2.5 Pro

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 45.0 on the Noometry Index. Gemini 2.5 Pro costs 5.8× less per token, which makes it the better buy when Claude Fable 5.1's lead doesn't matter for your workload.

Last verified . 38 shared benchmarks.

Claude Fable 5.1 Anthropic

69.0

Rank #2 Confirmed

Gemini 2.5 Pro Google

45.0

Rank #75 Confirmed

Summary

  • They share 38 benchmarks with published results for both. Claude Fable 5.1 scores higher in 9 categories and Gemini 2.5 Pro in 1 category; 10 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Fable 5.1 leads 89.6 to 32.5.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 87.8% for Claude Fable 5.1 and 0% for Gemini 2.5 Pro.
  • Gemini 2.5 Pro is cheaper at $1.25 / $10 per million input/output tokens, against $10 / $50 for Claude Fable 5.1.
  • Gemini 2.5 Pro accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Fable 5.1Gemini 2.5 Pro
ProviderAnthropicGoogle
Noometry Index69.045.0
Released2026-09-012025-03-25
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K66K
Input $ / M tokens$10$1.25
Output $ / M tokens$50$10
Results tracked5278

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Category by category

Coding Claude Fable 5.1 leads

Claude Fable 5.1: 74.7 (#1), Gemini 2.5 Pro: 42.4 (#101)

BenchmarkClaude Fable 5.1Gemini 2.5 Pro
LMArena WebDev17441227
SciCode63.1%42.8%
GSO88.2%3.9%
WeirdML92.9%54%
LMArena Coding15281452
ALE-Bench2,143785.52
SWE-bench Verified—57.6%
FrontierCode50.9%—
SWE-bench Verified (bash only)—53.6%
Aider Polyglot—83.1%
CursorBench51.8%—
FrontierSWE56.3%—
LiveBench Coding—85.9%
MirrorCode73.3%—
CadEval—64%
AlgoTune—1.51

Agentic & Tool Use Claude Fable 5.1 leads

Claude Fable 5.1: 50.7 (#5), Gemini 2.5 Pro: 29.2 (#88)

BenchmarkClaude Fable 5.1Gemini 2.5 Pro
Remote Labor Index17.9%0.8%
Vending-Bench 25,422573.64
Terminal-Bench—32.6%
APEX-Agents68.6%—
GDPval—23.3%
TheAgentCompany—30.3%
τ²-bench Banking—13.7%
DeepResearch Bench—42.8%
BALROG—43.3%
GDP.pdf29.6%—
LMArena Search—1142
METR Time Horizons—55.4%

Reasoning Claude Fable 5.1 leads

Claude Fable 5.1: 76.7 (#7), Gemini 2.5 Pro: 28.8 (#99)

BenchmarkClaude Fable 5.1Gemini 2.5 Pro
ARC-AGI-290%4.9%
ARC-AGI-197.5%41%
CritPt31.1%2%
Chess Puzzles47%20%
LMArena Hard Prompts15261455
DTBench97.6%82.4%
LMCA65.5%34.8%
Epoch Capabilities Index164.7145.32
SimpleBench—62.4%
Kagi LLM Benchmark—70.3%
NYT Connections (extended)90%—
EnigmaEval—5.6%
EBR-Bench57.1%—
LiveBench Reasoning—89.8%
Mystery Game Puzzles58%—
LiveBench Data Analysis—79.9%
ForecastBench—61.3
LiveBench—82.3%

Math Claude Fable 5.1 leads

Claude Fable 5.1: 89.6 (#4), Gemini 2.5 Pro: 32.5 (#213)

BenchmarkClaude Fable 5.1Gemini 2.5 Pro
FrontierMath (Tiers 1-3)90.2%24.6%
FrontierMath Tier 487.8%0%
OTIS Mock AIME 2024-2025100%84.7%
LMArena Math15251450
ProofBench100%—
Omni-MATH—41.6%
LiveBench Math—90.2%
MATH Level 5—95.9%
FrontierMath (Feb 2025 set)—14.1%
FrontierMath Erdős0%—
FrontierMath Tier 4 (v1)—4.2%

Knowledge Claude Fable 5.1 leads

Claude Fable 5.1: 69.6 (#6), Gemini 2.5 Pro: 56.0 (#46)

BenchmarkClaude Fable 5.1Gemini 2.5 Pro
Humanity's Last Exam46.5%21.6%
LMArena Expert15351452
GPQA Diamond—85.3%
SimpleQA Verified70.8%—
MMLU-Pro—86.3%
Confabulations—10.6%
Vectara Hallucination Rate—7%
GPQA (HELM)—74.9%

Multimodal Claude Fable 5.1 leads

Claude Fable 5.1: 53.9 (#4), Gemini 2.5 Pro: 45.2 (#18)

BenchmarkClaude Fable 5.1Gemini 2.5 Pro
LMArena Vision13181263
LMArena Document15131421
GeoBench—86%
VPCT—48%
Blueprint-Bench 241.9%—
Furniture Assembly70%—
SpatialViz-Bench—44.7%

Multilingual Claude Fable 5.1 leads

Claude Fable 5.1: 59.1 (#3), Gemini 2.5 Pro: 55.3 (#31)

BenchmarkClaude Fable 5.1Gemini 2.5 Pro
LMArena Non-English15071451
LMArena Chinese15861507
LMArena French15251472
LMArena German15001487
LMArena Japanese15431461
LMArena Korean15341434
LMArena Russian15211461
LMArena Spanish15161473

Instruction Following Claude Fable 5.1 leads

Claude Fable 5.1: 79.2 (#6), Gemini 2.5 Pro: 75.0 (#75)

BenchmarkClaude Fable 5.1Gemini 2.5 Pro
LMArena Instruction Following15171437
LiveBench Instruction Following—80.6%
IFEval—84%

Long Context Gemini 2.5 Pro leads

Claude Fable 5.1: 46.7 (#20), Gemini 2.5 Pro: 59.8 (#5)

BenchmarkClaude Fable 5.1Gemini 2.5 Pro
LMArena Longer Query15221449
Fiction.LiveBench—91.7%

Writing & Preference Claude Fable 5.1 leads

Claude Fable 5.1: 79.2 (#2), Gemini 2.5 Pro: 63.7 (#62)

BenchmarkClaude Fable 5.1Gemini 2.5 Pro
LMArena Text15101458
LMArena Creative Writing15071454
EQ-Bench Creative Writing21621421
LMArena Multi-Turn14921453
Short-Story Creative Writing—83.8%
WildBench—85.7%
LiveBench Language—67.8%

Frequently asked questions

Is Claude Fable 5.1 better than Gemini 2.5 Pro?

Claude Fable 5.1 is the stronger model overall, scoring 69.0 to 45.0 on the Noometry Index. Gemini 2.5 Pro costs 5.8× 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 Gemini 2.5 Pro?

Gemini 2.5 Pro is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; Claude Fable 5.1 lists at $10 and $50.

Is Claude Fable 5.1 or Gemini 2.5 Pro better for coding?

Claude Fable 5.1 scores higher on coding benchmarks: 74.7 versus 42.4 in the Noometry coding category.

Which has the bigger context window?

Gemini 2.5 Pro does, with 1.05M tokens against 1M.

How many benchmarks do Claude Fable 5.1 and Gemini 2.5 Pro share?

38 benchmarks have published results for both models. Claude Fable 5.1 has 52 scored results on Noometry and Gemini 2.5 Pro has 78.

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