Noometry

Model comparison

Claude Sonnet 5 vs Gemini 2.5 Flash

Claude Sonnet 5 is the stronger model overall, scoring 54.5 to 39.0 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

54.5

Rank #26 Confirmed

Gemini 2.5 Flash Google

39.0

Rank #162 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; 9 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Sonnet 5 leads 48.2 to 18.2.
  • 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 Index54.539.0
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

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding Claude Sonnet 5 leads

Claude Sonnet 5: 55.5 (#20), Gemini 2.5 Flash: 35.5 (#210)

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 WebDev1540—
SciCode53.6%—
GSO37.3%—

Agentic & Tool Use Claude Sonnet 5 leads

Claude Sonnet 5: 42.7 (#16), Gemini 2.5 Flash: 30.6 (#67)

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: 48.2 (#37), Gemini 2.5 Flash: 18.2 (#271)

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 Index156.34143.04
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: 66.1 (#21), Gemini 2.5 Flash: 38.1 (#87)

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: 55.7 (#42), Gemini 2.5 Flash: 36.1 (#162)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Expert14911426
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 Claude Sonnet 5 leads

Claude Sonnet 5: 42.4 (#26), Gemini 2.5 Flash: 41.2 (#31)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Vision12751254
GeoBench—76%
VPCT—46.2%
Blueprint-Bench 224.9%—
LMArena Document1466—
SpatialViz-Bench—36.9%

Multilingual Claude Sonnet 5 leads

Claude Sonnet 5: 54.0 (#55), Gemini 2.5 Flash: 52.5 (#83)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Non-English14311410
LMArena Chinese14751450
LMArena French14571433
LMArena German14481419
LMArena Japanese14221403
LMArena Korean14111385
LMArena Russian14521415
LMArena Spanish14361421

Instruction Following Too close to call

Claude Sonnet 5: 76.6 (#39), Gemini 2.5 Flash: 75.9 (#50)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Instruction Following14531405
IFEval—89.8%

Long Context Gemini 2.5 Flash leads

Claude Sonnet 5: 44.8 (#53), Gemini 2.5 Flash: 47.5 (#16)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Longer Query14641419
Fiction.LiveBench—77.8%

Writing & Preference Claude Sonnet 5 leads

Claude Sonnet 5: 69.4 (#24), Gemini 2.5 Flash: 54.0 (#153)

BenchmarkClaude Sonnet 5Gemini 2.5 Flash
LMArena Text14431417
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 54.5 to 39.0 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 35.5 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.

Related comparisons

Go deeper