Model comparison

Claude Sonnet 4.5 vs Gemini 3.5 Flash

Gemini 3.5 Flash is the stronger model overall, scoring 54.2 to 44.1 on the Noometry Index.

Last verified . 45 shared benchmarks.

Claude Sonnet 4.5 Anthropic

44.1

Rank #81 Confirmed

Gemini 3.5 Flash Google

54.2

Rank #32 Confirmed

Summary

  • They share 45 benchmarks with published results for both. Claude Sonnet 4.5 scores higher in 2 categories and Gemini 3.5 Flash in 8 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.5 Flash leads 62.8 to 26.9.
  • The biggest single-benchmark swing is ARC-AGI-2: 13.6% for Claude Sonnet 4.5 and 72.1% for Gemini 3.5 Flash.
  • Gemini 3.5 Flash is cheaper at $1.50 / $9 per million input/output tokens, against $3 / $15 for Claude Sonnet 4.5.
  • Gemini 3.5 Flash accepts more context: 1.05M tokens versus 200K.

Side by side

Claude Sonnet 4.5 and Gemini 3.5 Flash specifications
Claude Sonnet 4.5Gemini 3.5 Flash
ProviderAnthropicGoogle
Noometry Index44.154.2
Released2025-09-292026-05-19
WeightsProprietaryProprietary
Context window200K1.05M
Max output64K66K
Input $ / M tokens$3$1.50
Output $ / M tokens$15$9
Results tracked7354

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Category by category

Coding Gemini 3.5 Flash leads

Claude Sonnet 4.5: 47.3 (#61), Gemini 3.5 Flash: 49.4 (#49)

Coding benchmarks
BenchmarkClaude Sonnet 4.5Gemini 3.5 Flash
SWE-bench Verified71.3%79.3%
LMArena WebDev13931499
SciCode44.7%53.1%
WeirdML47.7%62.6%
LMArena Coding14891492
ALE-Bench796.15911.02
DeepSWE—37.4%
SWE-bench Verified (bash only)71.4%—
SWE-bench Multilingual67%—
GSO14.7%—
AlgoTune1.52—

Agentic & Tool Use Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 38.3 (#32), Gemini 3.5 Flash: 24.7 (#114)

Agentic & Tool Use benchmarks
BenchmarkClaude Sonnet 4.5Gemini 3.5 Flash
Vending-Bench 23,8395,396
Terminal-Bench46.5%—
APEX-Agents—27.5%
Berkeley Function Calling Leaderboard73.2%—
GDPval42.5%—
Remote Labor Index2.1%—
τ²-bench Airline72%—
τ²-bench Banking25.3%—
τ²-bench Retail72.4%—
τ²-bench Telecom84.9%—
Cybench60%—
DeepResearch Bench52.6%—
OSWorld62.9%—
GBAEval—6.7%
GDP.pdf—14%
LMArena Search1159—
METR Time Horizons67.4%—

Reasoning Gemini 3.5 Flash leads

Claude Sonnet 4.5: 26.9 (#125), Gemini 3.5 Flash: 62.8 (#18)

Reasoning benchmarks
BenchmarkClaude Sonnet 4.5Gemini 3.5 Flash
ARC-AGI-213.6%72.1%
SimpleBench54.3%76.7%
NYT Connections (extended)37.3%92.6%
ARC-AGI-163.7%92.5%
CritPt1.1%13.1%
Chess Puzzles12%50%
EnigmaEval6%25.4%
EBR-Bench2.4%4.8%
LMArena Hard Prompts14621488
Mystery Game Puzzles17%32%
DTBench83.2%94.7%
LMCA38.8%47.1%
Epoch Capabilities Index146.84154.46
ForecastBench61.959
Kagi LLM Benchmark57.9%—
Surface Evolver Bench—58.1%

Math Gemini 3.5 Flash leads

Claude Sonnet 4.5: 32.3 (#216), Gemini 3.5 Flash: 60.7 (#36)

Math benchmarks
BenchmarkClaude Sonnet 4.5Gemini 3.5 Flash
FrontierMath (Tiers 1-3)23.9%62.8%
FrontierMath Tier 42.4%26.8%
OTIS Mock AIME 2024-202577.8%95.6%
ProofBench19%31%
LMArena Math14491504
FrontierMath (Feb 2025 set)15.2%39%
FrontierMath Tier 4 (v1)4.2%14.6%
MathArena Final-Answer Competitions—76.3%
Omni-MATH55.3%—
MATH Level 597.7%—

Knowledge Gemini 3.5 Flash leads

Claude Sonnet 4.5: 48.4 (#76), Gemini 3.5 Flash: 66.3 (#11)

Knowledge benchmarks
BenchmarkClaude Sonnet 4.5Gemini 3.5 Flash
GPQA Diamond82.3%92.8%
SimpleQA Verified30.7%66.2%
LMArena Expert14821495
Humanity's Last Exam13.7%—
MMLU-Pro86.9%—
Vectara Hallucination Rate12%—
GPQA (HELM)68.6%—

Multimodal Gemini 3.5 Flash leads

Claude Sonnet 4.5: 34.8 (#89), Gemini 3.5 Flash: 45.7 (#15)

Multimodal benchmarks
BenchmarkClaude Sonnet 4.5Gemini 3.5 Flash
LMArena Document14501463
LMArena Vision—1310
VPCT39.8%—
Blueprint-Bench 2—33.6%

Multilingual Gemini 3.5 Flash leads

Claude Sonnet 4.5: 53.4 (#69), Gemini 3.5 Flash: 57.0 (#13)

Multilingual benchmarks
BenchmarkClaude Sonnet 4.5Gemini 3.5 Flash
LMArena Non-English14251476
LMArena Chinese14591526
LMArena French14581490
LMArena German14271492
LMArena Japanese13901486
LMArena Korean14031451
LMArena Russian14371493
LMArena Spanish14571480

Instruction Following Gemini 3.5 Flash leads

Claude Sonnet 4.5: 75.0 (#78), Gemini 3.5 Flash: 77.0 (#30)

Instruction Following benchmarks
BenchmarkClaude Sonnet 4.5Gemini 3.5 Flash
LMArena Instruction Following14591467
IFEval85%—

Long Context Too close to call

Claude Sonnet 4.5: 45.2 (#46), Gemini 3.5 Flash: 45.4 (#38)

Long Context benchmarks
BenchmarkClaude Sonnet 4.5Gemini 3.5 Flash
LMArena Longer Query14761482

Writing & Preference Claude Sonnet 4.5 leads

Claude Sonnet 4.5: 66.5 (#34), Gemini 3.5 Flash: 65.5 (#47)

Writing & Preference benchmarks
BenchmarkClaude Sonnet 4.5Gemini 3.5 Flash
LMArena Text14391482
LMArena Creative Writing14421470
LMArena Multi-Turn14651481
EQ-Bench Creative Writing1678—
WildBench85.4%—
EQ-Bench 4—1087

Frequently asked questions

Is Claude Sonnet 4.5 better than Gemini 3.5 Flash?

Gemini 3.5 Flash is the stronger model overall, scoring 54.2 to 44.1 on the Noometry Index.

Which is cheaper, Claude Sonnet 4.5 or Gemini 3.5 Flash?

Gemini 3.5 Flash is cheaper. It lists at $1.50 per million input tokens and $9 per million output tokens; Claude Sonnet 4.5 lists at $3 and $15.

Is Claude Sonnet 4.5 or Gemini 3.5 Flash better for coding?

Gemini 3.5 Flash scores higher on coding benchmarks: 49.4 versus 47.3 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.5 Flash does, with 1.05M tokens against 200K.

How many benchmarks do Claude Sonnet 4.5 and Gemini 3.5 Flash share?

45 benchmarks have published results for both models. Claude Sonnet 4.5 has 73 scored results on Noometry and Gemini 3.5 Flash has 54.

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