Noometry

Model comparison

Claude Fable 5 vs Gemini 2.5 Flash

Claude Fable 5 is the stronger model overall, scoring 66.8 to 39.3 on the Noometry Index. Gemini 2.5 Flash costs 24× less per token, which makes it the better buy when Claude Fable 5's lead doesn't matter for your workload.

Last verified . 32 shared benchmarks.

Claude Fable 5 Anthropic

66.8

Rank #5 Confirmed

Gemini 2.5 Flash Google

39.3

Rank #170 Confirmed

Summary

  • They share 32 benchmarks with published results for both. Claude Fable 5 scores higher in 9 categories and Gemini 2.5 Flash in 1 category; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Fable 5 leads 76.8 to 18.1.
  • The biggest single-benchmark swing is ARC-AGI-2: 89.2% for Claude Fable 5 and 2.5% for Gemini 2.5 Flash.
  • Gemini 2.5 Flash is cheaper at $0.30 / $2.50 per million input/output tokens, against $10 / $50 for Claude Fable 5.
  • Gemini 2.5 Flash accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Fable 5Gemini 2.5 Flash
ProviderAnthropicGoogle
Noometry Index66.839.3
Released2026-06-072025-04-17
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K66K
Input $ / M tokens$10$0.30
Output $ / M tokens$50$2.50
Results tracked6254

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Category by category

Coding Claude Fable 5 leads

Claude Fable 5: 70.6 (#4), Gemini 2.5 Flash: 35.8 (#220)

BenchmarkClaude Fable 5Gemini 2.5 Flash
WeirdML91.9%41.9%
LMArena Coding15191424
ALE-Bench2,041661.88
DeepSWE69.9%—
FrontierCode53.5%—
SWE-bench Verified (bash only)—28.7%
Aider Polyglot—55.1%
LMArena WebDev1625—
FrontierSWE47%—
SciCode61%—
GSO78.4%—
MirrorCode63.9%—

Agentic & Tool Use Claude Fable 5 leads

Claude Fable 5: 54.0 (#2), Gemini 2.5 Flash: 30.8 (#74)

BenchmarkClaude Fable 5Gemini 2.5 Flash
Vending-Bench 25,680548.84
Terminal-Bench—17.1%
APEX-Agents63.6%—
Berkeley Function Calling Leaderboard—56.2%
Remote Labor Index16.1%—
TheAgentCompany—41.1%
τ²-bench Banking39.7%—
PostTrainBench41.8%—
BALROG—33.5%
GBAEval74.5%—
GDP.pdf30%—
LMArena Search1230—

Reasoning Claude Fable 5 leads

Claude Fable 5: 76.8 (#6), Gemini 2.5 Flash: 18.1 (#286)

BenchmarkClaude Fable 5Gemini 2.5 Flash
ARC-AGI-289.2%2.5%
SimpleBench81.9%41.2%
Kagi LLM Benchmark91.4%56.8%
ARC-AGI-198.5%33.3%
CritPt28.6%1.1%
EnigmaEval39.3%2.7%
LMArena Hard Prompts15081422
DTBench98.4%76.5%
LMCA61.1%27.5%
Epoch Capabilities Index162.06143.03
NYT Connections (extended)92.7%—
Chess Puzzles41%—
EBR-Bench39.5%—
Mystery Game Puzzles52%—
Surface Evolver Bench95%—
Bench to the Future 30.13—
ForecastBench—60.6

Math Claude Fable 5 leads

Claude Fable 5: 88.5 (#5), Gemini 2.5 Flash: 39.9 (#98)

BenchmarkClaude Fable 5Gemini 2.5 Flash
OTIS Mock AIME 2024-2025100%73.1%
LMArena Math15191415
FrontierMath (Tiers 1-3)87%—
FrontierMath Tier 490.2%—
ProofBench95%—
Omni-MATH—38.5%
FrontierMath (Feb 2025 set)—4.8%
FrontierMath Erdős0%—
FrontierMath Tier 4 (v1)—4.2%

Knowledge Claude Fable 5 leads

Claude Fable 5: 62.2 (#25), Gemini 2.5 Flash: 36.4 (#168)

BenchmarkClaude Fable 5Gemini 2.5 Flash
LMArena Expert15341426
GPQA Diamond85.9%—
Humanity's Last Exam—12.1%
SimpleQA Verified70.7%—
MMLU-Pro—63.9%
Confabulations—16.8%
Vectara Hallucination Rate—7.8%
GPQA (HELM)—39%

Multimodal Claude Fable 5 leads

Claude Fable 5: 45.3 (#17), Gemini 2.5 Flash: 41.8 (#32)

BenchmarkClaude Fable 5Gemini 2.5 Flash
LMArena Vision13241253
GeoBench—76%
VPCT—46.2%
Blueprint-Bench 238.6%—
Furniture Assembly35.8%—
LMArena Document1496—
SpatialViz-Bench—36.9%

Multilingual Claude Fable 5 leads

Claude Fable 5: 57.3 (#9), Gemini 2.5 Flash: 52.3 (#88)

BenchmarkClaude Fable 5Gemini 2.5 Flash
LMArena Non-English14811409
LMArena Chinese15431450
LMArena French15051433
LMArena German14861418
LMArena Japanese15061405
LMArena Korean14881385
LMArena Russian15041415
LMArena Spanish14981421

Instruction Following Claude Fable 5 leads

Claude Fable 5: 78.6 (#8), Gemini 2.5 Flash: 75.7 (#54)

BenchmarkClaude Fable 5Gemini 2.5 Flash
LMArena Instruction Following15021405
IFEval—89.8%

Long Context Gemini 2.5 Flash leads

Claude Fable 5: 46.3 (#23), Gemini 2.5 Flash: 47.5 (#17)

BenchmarkClaude Fable 5Gemini 2.5 Flash
LMArena Longer Query15091419
Fiction.LiveBench—77.8%

Writing & Preference Claude Fable 5 leads

Claude Fable 5: 75.9 (#5), Gemini 2.5 Flash: 53.8 (#157)

BenchmarkClaude Fable 5Gemini 2.5 Flash
LMArena Text14911417
LMArena Creative Writing14941400
EQ-Bench Creative Writing19431137
LMArena Multi-Turn15041408
Short-Story Creative Writing—76.5%
WildBench—81.7%
EQ-Bench 41340—

Frequently asked questions

Is Claude Fable 5 better than Gemini 2.5 Flash?

Claude Fable 5 is the stronger model overall, scoring 66.8 to 39.3 on the Noometry Index. Gemini 2.5 Flash costs 24× less per token, which makes it the better buy when Claude Fable 5's lead doesn't matter for your workload.

Which is cheaper, Claude Fable 5 or Gemini 2.5 Flash?

Gemini 2.5 Flash is cheaper. It lists at $0.30 per million input tokens and $2.50 per million output tokens; Claude Fable 5 lists at $10 and $50.

Is Claude Fable 5 or Gemini 2.5 Flash better for coding?

Claude Fable 5 scores higher on coding benchmarks: 70.6 versus 35.8 in the Noometry coding category.

Which has the bigger context window?

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

How many benchmarks do Claude Fable 5 and Gemini 2.5 Flash share?

32 benchmarks have published results for both models. Claude Fable 5 has 62 scored results on Noometry and Gemini 2.5 Flash has 54.

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