Model comparison

Claude Sonnet 4 vs Gemini 2.5 Flash

Claude Sonnet 4 is the stronger model overall, scoring 40.8 to 39.3 on the Noometry Index. Gemini 2.5 Flash costs 7.1× less per token, which makes it the better buy when Claude Sonnet 4's lead doesn't matter for your workload.

Last verified . 49 shared benchmarks.

Claude Sonnet 4 Anthropic

40.8

Rank #145 Confirmed

Gemini 2.5 Flash Google

39.3

Rank #170 Confirmed

Summary

  • They share 49 benchmarks with published results for both. Claude Sonnet 4 scores higher in 6 categories and Gemini 2.5 Flash in 4 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in multimodal, where Gemini 2.5 Flash leads 41.8 to 26.2.
  • The biggest single-benchmark swing is GeoBench: 37% for Claude Sonnet 4 and 76% for Gemini 2.5 Flash.
  • Gemini 2.5 Flash is cheaper at $0.30 / $2.50 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.
  • Gemini 2.5 Flash accepts more context: 1.05M tokens versus 200K.

Side by side

Claude Sonnet 4 and Gemini 2.5 Flash specifications
Claude Sonnet 4Gemini 2.5 Flash
ProviderAnthropicGoogle
Noometry Index40.839.3
Released2025-05-222025-04-17
WeightsProprietaryProprietary
Context window200K1.05M
Max output64K66K
Input $ / M tokens$3$0.30
Output $ / M tokens$15$2.50
Results tracked5854

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Category by category

Coding Claude Sonnet 4 leads

Claude Sonnet 4: 43.5 (#88), Gemini 2.5 Flash: 35.8 (#220)

Coding benchmarks
BenchmarkClaude Sonnet 4Gemini 2.5 Flash
SWE-bench Verified (bash only)64.9%28.7%
Aider Polyglot61.3%55.1%
WeirdML46.1%41.9%
LMArena Coding14141424
ALE-Bench655.35661.88
SciCode40%—
GSO4.9%—

Agentic & Tool Use Claude Sonnet 4 leads

Claude Sonnet 4: 38.5 (#31), Gemini 2.5 Flash: 30.8 (#74)

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 4Gemini 2.5 Flash
TheAgentCompany33.1%41.1%
Terminal-Bench—17.1%
Berkeley Function Calling Leaderboard—56.2%
Cybench35%—
DeepResearch Bench46.6%—
OSWorld43.9%—
BALROG—33.5%
METR Time Horizons62%—
Vending-Bench 2—548.84

Reasoning Claude Sonnet 4 leads

Claude Sonnet 4: 22.9 (#187), Gemini 2.5 Flash: 18.1 (#286)

Reasoning benchmarks
BenchmarkClaude Sonnet 4Gemini 2.5 Flash
ARC-AGI-25.9%2.5%
SimpleBench45.5%41.2%
Kagi LLM Benchmark73%56.8%
ARC-AGI-140%33.3%
CritPt0.3%1.1%
EnigmaEval3.1%2.7%
LMArena Hard Prompts13721422
DTBench77.1%76.5%
LMCA29%27.5%
Epoch Capabilities Index141.69143.03
ForecastBench60.260.6

Math Claude Sonnet 4 leads

Claude Sonnet 4: 43.3 (#80), Gemini 2.5 Flash: 39.9 (#98)

Math benchmarks
BenchmarkClaude Sonnet 4Gemini 2.5 Flash
OTIS Mock AIME 2024-202571.1%73.1%
Omni-MATH60.2%38.5%
LMArena Math13751415
FrontierMath (Feb 2025 set)4.1%4.8%
FrontierMath Tier 4 (v1)0%4.2%
MATH Level 584.4%—

Knowledge Claude Sonnet 4 leads

Claude Sonnet 4: 41.8 (#108), Gemini 2.5 Flash: 36.4 (#168)

Knowledge benchmarks
BenchmarkClaude Sonnet 4Gemini 2.5 Flash
Humanity's Last Exam7.8%12.1%
MMLU-Pro84.3%63.9%
Confabulations13.2%16.8%
Vectara Hallucination Rate10.3%7.8%
GPQA (HELM)70.6%39%
LMArena Expert13721426
GPQA Diamond79.2%—

Multimodal Gemini 2.5 Flash leads

Claude Sonnet 4: 26.2 (#121), Gemini 2.5 Flash: 41.8 (#32)

Multimodal benchmarks
BenchmarkClaude Sonnet 4Gemini 2.5 Flash
LMArena Vision11911253
GeoBench37%76%
VPCT34%46.2%
MindCube44.8%—
SpatialViz-Bench—36.9%

Multilingual Gemini 2.5 Flash leads

Claude Sonnet 4: 46.7 (#156), Gemini 2.5 Flash: 52.3 (#88)

Multilingual benchmarks
BenchmarkClaude Sonnet 4Gemini 2.5 Flash
LMArena Non-English13331409
LMArena Chinese13501450
LMArena French13631433
LMArena German13311418
LMArena Japanese13021405
LMArena Korean12911385
LMArena Russian13551415
LMArena Spanish13571421

Instruction Following Gemini 2.5 Flash leads

Claude Sonnet 4: 71.7 (#145), Gemini 2.5 Flash: 75.7 (#54)

Instruction Following benchmarks
BenchmarkClaude Sonnet 4Gemini 2.5 Flash
IFEval84%89.8%
LMArena Instruction Following13761405

Long Context Gemini 2.5 Flash leads

Claude Sonnet 4: 33.7 (#259), Gemini 2.5 Flash: 47.5 (#17)

Long Context benchmarks
BenchmarkClaude Sonnet 4Gemini 2.5 Flash
Fiction.LiveBench46.9%77.8%
LMArena Longer Query13981419

Writing & Preference Claude Sonnet 4 leads

Claude Sonnet 4: 57.1 (#132), Gemini 2.5 Flash: 53.8 (#157)

Writing & Preference benchmarks
BenchmarkClaude Sonnet 4Gemini 2.5 Flash
LMArena Text13511417
LMArena Creative Writing13451400
Short-Story Creative Writing81.4%76.5%
EQ-Bench Creative Writing14831137
WildBench83.8%81.7%
LMArena Multi-Turn13761408

Frequently asked questions

Is Claude Sonnet 4 better than Gemini 2.5 Flash?

Claude Sonnet 4 is the stronger model overall, scoring 40.8 to 39.3 on the Noometry Index. Gemini 2.5 Flash costs 7.1× less per token, which makes it the better buy when Claude Sonnet 4's lead doesn't matter for your workload.

Which is cheaper, Claude Sonnet 4 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 4 lists at $3 and $15.

Is Claude Sonnet 4 or Gemini 2.5 Flash better for coding?

Claude Sonnet 4 scores higher on coding benchmarks: 43.5 versus 35.8 in the Noometry coding category.

Which has the bigger context window?

Gemini 2.5 Flash does, with 1.05M tokens against 200K.

How many benchmarks do Claude Sonnet 4 and Gemini 2.5 Flash share?

49 benchmarks have published results for both models. Claude Sonnet 4 has 58 scored results on Noometry and Gemini 2.5 Flash has 54.

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