Noometry

Model comparison

Claude Opus 5.5 vs Gemini 3 Flash Preview

Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 52.3 on the Noometry Index. Gemini 3 Flash Preview costs 7.1× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Last verified . 25 shared benchmarks.

Claude Opus 5.5 Anthropic

68.5

Rank #3 Confirmed

Gemini 3 Flash Preview Google

52.3

Rank #33 Confirmed

Summary

  • They share 25 benchmarks with published results for both. Claude Opus 5.5 scores higher in 10 categories and Gemini 3 Flash Preview in 0 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 5.5 leads 92.4 to 51.4.
  • The biggest single-benchmark swing is ProofBench: 100% for Claude Opus 5.5 and 15% for Gemini 3 Flash Preview.
  • Gemini 3 Flash Preview is cheaper at $0.50 / $3 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
  • Gemini 3 Flash Preview accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Opus 5.5Gemini 3 Flash Preview
ProviderAnthropicGoogle
Noometry Index68.552.3
Released2026-09-222025-12-17
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K66K
Input $ / M tokens$4$0.50
Output $ / M tokens$20$3
Results tracked3559

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Category by category

Coding Claude Opus 5.5 leads

Claude Opus 5.5: 71.4 (#1), Gemini 3 Flash Preview: 51.5 (#35)

BenchmarkClaude Opus 5.5Gemini 3 Flash Preview
LMArena WebDev18201439
LMArena Coding15451460
SWE-bench Verified—75.4%
FrontierCode54.4%—
SWE-bench Verified (bash only)—75.8%
CursorBench57.8%—
SWE-bench Multilingual—72.7%
FrontierSWE62.3%—
SciCode66.9%—
GSO—9.8%
WeirdML—61.6%
MirrorCode77.4%—
ALE-Bench—1,367

Agentic & Tool Use Claude Opus 5.5 leads

Claude Opus 5.5: 45.3 (#13), Gemini 3 Flash Preview: 38.6 (#27)

BenchmarkClaude Opus 5.5Gemini 3 Flash Preview
GDP.pdf30.6%10%
Terminal-Bench—64.3%
APEX-Agents73.5%—
τ²-bench Airline—82.5%
τ²-bench Banking—27.3%
τ²-bench Retail—76.8%
τ²-bench Telecom—91.2%
DeepResearch Bench—49.8%
BALROG—48.1%
LMArena Search—1198
Vending-Bench 2—3,635

Reasoning Claude Opus 5.5 leads

Claude Opus 5.5: 79.5 (#2), Gemini 3 Flash Preview: 49.2 (#35)

BenchmarkClaude Opus 5.5Gemini 3 Flash Preview
ARC-AGI-292.5%33.6%
NYT Connections (extended)88.5%83.1%
ARC-AGI-197.5%84.7%
LMArena Hard Prompts15451465
Mystery Game Puzzles71%26%
DTBench98.9%89.1%
LMCA68.2%43.1%
SimpleBench—61.1%
CritPt31.7%—
Chess Puzzles—40%
EBR-Bench71.4%—
Epoch Capabilities Index—151.83
ForecastBench—58.5

Math Claude Opus 5.5 leads

Claude Opus 5.5: 92.4 (#2), Gemini 3 Flash Preview: 51.4 (#42)

BenchmarkClaude Opus 5.5Gemini 3 Flash Preview
FrontierMath (Tiers 1-3)91.2%51.2%
FrontierMath Tier 495%17.1%
OTIS Mock AIME 2024-2025100%95.6%
ProofBench100%15%
MathArena Final-Answer Competitions—67.6%
LMArena Math—1472
FrontierMath (Feb 2025 set)—35.6%
FrontierMath Tier 4 (v1)—4.2%

Knowledge Claude Opus 5.5 leads

Claude Opus 5.5: 66.6 (#9), Gemini 3 Flash Preview: 58.8 (#30)

BenchmarkClaude Opus 5.5Gemini 3 Flash Preview
GPQA Diamond90.6%89.4%
SimpleQA Verified72.2%66.8%
LMArena Expert15641461
Vectara Hallucination Rate—13.5%

Multimodal Claude Opus 5.5 leads

Claude Opus 5.5: 56.5 (#2), Gemini 3 Flash Preview: 45.3 (#15)

BenchmarkClaude Opus 5.5Gemini 3 Flash Preview
LMArena Vision—1285
GeoBench—88%
VPCT—72.6%
Blueprint-Bench 2—0%
Furniture Assembly83.3%—
LMArena Document—1413

Multilingual Claude Opus 5.5 leads

Claude Opus 5.5: 59.8 (#1), Gemini 3 Flash Preview: 55.9 (#26)

BenchmarkClaude Opus 5.5Gemini 3 Flash Preview
LMArena Non-English15131458
LMArena Chinese15721510
LMArena Russian15321480
LMArena French—1478
LMArena German—1497
LMArena Japanese—1488
LMArena Korean—1443
LMArena Spanish—1470

Instruction Following Claude Opus 5.5 leads

Claude Opus 5.5: 80.1 (#2), Gemini 3 Flash Preview: 75.8 (#52)

BenchmarkClaude Opus 5.5Gemini 3 Flash Preview
LMArena Instruction Following15351437

Long Context Claude Opus 5.5 leads

Claude Opus 5.5: 47.3 (#18), Gemini 3 Flash Preview: 44.4 (#63)

BenchmarkClaude Opus 5.5Gemini 3 Flash Preview
LMArena Longer Query15401452

Writing & Preference Claude Opus 5.5 leads

Claude Opus 5.5: 78.7 (#3), Gemini 3 Flash Preview: 65.6 (#44)

BenchmarkClaude Opus 5.5Gemini 3 Flash Preview
LMArena Text15181466
LMArena Creative Writing15381457
LMArena Multi-Turn15201471
EQ-Bench Creative Writing2050—

Frequently asked questions

Is Claude Opus 5.5 better than Gemini 3 Flash Preview?

Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 52.3 on the Noometry Index. Gemini 3 Flash Preview costs 7.1× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 5.5 or Gemini 3 Flash Preview?

Gemini 3 Flash Preview is cheaper. It lists at $0.50 per million input tokens and $3 per million output tokens; Claude Opus 5.5 lists at $4 and $20.

Is Claude Opus 5.5 or Gemini 3 Flash Preview better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.4 versus 51.5 in the Noometry coding category.

Which has the bigger context window?

Gemini 3 Flash Preview does, with 1.05M tokens against 1M.

How many benchmarks do Claude Opus 5.5 and Gemini 3 Flash Preview share?

25 benchmarks have published results for both models. Claude Opus 5.5 has 35 scored results on Noometry and Gemini 3 Flash Preview has 59.

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