Noometry

Model comparison

Claude Sonnet 5 vs Gemini 2.5 Flash

Claude Sonnet 5 is the stronger model overall, scoring 54.6 to 39.3 on the Noometry Index. Gemini 2.5 Flash costs 4.7× less per token, which makes it the better buy when Claude Sonnet 5's lead doesn't matter for your workload.

Last verified . 29 shared benchmarks.

Claude Sonnet 5 Anthropic

54.6

Rank #29 Confirmed

Gemini 2.5 Flash Google

39.3

Rank #170 Confirmed

Summary

  • They share 29 benchmarks with published results for both. Claude Sonnet 5 scores higher in 9 categories and Gemini 2.5 Flash in 1 category; 8 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Sonnet 5 leads 49.1 to 18.1.
  • The biggest single-benchmark swing is WeirdML: 68.8% for Claude Sonnet 5 and 41.9% for Gemini 2.5 Flash.
  • Gemini 2.5 Flash is cheaper at $0.30 / $2.50 per million input/output tokens, against $2 / $10 for Claude Sonnet 5.
  • Gemini 2.5 Flash accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Sonnet 5Gemini 2.5 Flash
ProviderAnthropicGoogle
Noometry Index54.639.3
Released2026-06-292025-04-17
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K66K
Input $ / M tokens$2$0.30
Output $ / M tokens$10$2.50
Results tracked5154

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Category by category

Coding Claude Sonnet 5 leads

Claude Sonnet 5: 55.5 (#26), Gemini 2.5 Flash: 35.8 (#220)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
WeirdML68.8%41.9%
LMArena Coding14831424
ALE-Bench1,463661.88
DeepSWE53.8%—
FrontierCode42.7%—
SWE-bench Verified (bash only)—28.7%
Aider Polyglot—55.1%
CursorBench34.1%—
LMArena WebDev1541—
SciCode54.3%—
GSO37.3%—

Agentic & Tool Use Claude Sonnet 5 leads

Claude Sonnet 5: 42.8 (#18), Gemini 2.5 Flash: 30.8 (#74)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
Vending-Bench 26,378548.84
Terminal-Bench—17.1%
APEX-Agents54.5%—
Berkeley Function Calling Leaderboard—56.2%
TheAgentCompany—41.1%
BALROG—33.5%
GBAEval65.3%—
LMArena Search1194—

Reasoning Claude Sonnet 5 leads

Claude Sonnet 5: 49.1 (#39), Gemini 2.5 Flash: 18.1 (#286)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
SimpleBench60.6%41.2%
CritPt16.9%1.1%
LMArena Hard Prompts14611422
DTBench92.5%76.5%
LMCA50%27.5%
Epoch Capabilities Index156.21143.03
ForecastBench61.160.6
ARC-AGI-2—2.5%
Kagi LLM Benchmark—56.8%
NYT Connections (extended)75.1%—
ARC-AGI-1—33.3%
Chess Puzzles35%—
EnigmaEval—2.7%
Mystery Game Puzzles35%—
Surface Evolver Bench60%—
Bench to the Future 30.14—

Math Claude Sonnet 5 leads

Claude Sonnet 5: 66.2 (#27), Gemini 2.5 Flash: 39.9 (#98)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
OTIS Mock AIME 2024-202594.7%73.1%
LMArena Math14671415
FrontierMath (Tiers 1-3)65.6%—
FrontierMath Tier 429.3%—
ProofBench77%—
Omni-MATH—38.5%
FrontierMath (Feb 2025 set)—4.8%
FrontierMath Tier 4 (v1)—4.2%

Knowledge Claude Sonnet 5 leads

Claude Sonnet 5: 55.6 (#47), Gemini 2.5 Flash: 36.4 (#168)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Expert14901426
GPQA Diamond90.5%—
Humanity's Last Exam—12.1%
SimpleQA Verified33.7%—
MMLU-Pro—63.9%
Confabulations—16.8%
Vectara Hallucination Rate—7.8%
GPQA (HELM)—39%

Multimodal Too close to call

Claude Sonnet 5: 42.4 (#31), Gemini 2.5 Flash: 41.8 (#32)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Vision12741253
GeoBench—76%
VPCT—46.2%
Blueprint-Bench 224.9%—
LMArena Document1466—
SpatialViz-Bench—36.9%

Multilingual Claude Sonnet 5 leads

Claude Sonnet 5: 53.8 (#55), Gemini 2.5 Flash: 52.3 (#88)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Non-English14311409
LMArena Chinese14771450
LMArena French14601433
LMArena German14401418
LMArena Japanese14221405
LMArena Korean14111385
LMArena Russian14511415
LMArena Spanish14371421

Instruction Following Too close to call

Claude Sonnet 5: 76.3 (#41), Gemini 2.5 Flash: 75.7 (#54)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Instruction Following14521405
IFEval—89.8%

Long Context Gemini 2.5 Flash leads

Claude Sonnet 5: 44.8 (#55), Gemini 2.5 Flash: 47.5 (#17)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Longer Query14631419
Fiction.LiveBench—77.8%

Writing & Preference Claude Sonnet 5 leads

Claude Sonnet 5: 69.2 (#25), Gemini 2.5 Flash: 53.8 (#157)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Text14421417
LMArena Creative Writing14161400
EQ-Bench Creative Writing17941137
LMArena Multi-Turn14541408
Short-Story Creative Writing—76.5%
WildBench—81.7%
EQ-Bench 41236—

Frequently asked questions

Is Claude Sonnet 5 better than Gemini 2.5 Flash?

Claude Sonnet 5 is the stronger model overall, scoring 54.6 to 39.3 on the Noometry Index. Gemini 2.5 Flash costs 4.7× less per token, which makes it the better buy when Claude Sonnet 5's lead doesn't matter for your workload.

Which is cheaper, Claude Sonnet 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 Sonnet 5 lists at $2 and $10.

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

Claude Sonnet 5 scores higher on coding benchmarks: 55.5 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 Sonnet 5 and Gemini 2.5 Flash share?

29 benchmarks have published results for both models. Claude Sonnet 5 has 51 scored results on Noometry and Gemini 2.5 Flash has 54.

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