Model comparison

Claude Opus 4.5 vs Gemini 3.8 Flash

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 50.5 on the Noometry Index.

Last verified . 39 shared benchmarks.

Claude Opus 4.5 Anthropic

50.5

Rank #47 Confirmed

Gemini 3.8 Flash Google

61.8

Rank #11 Confirmed

Summary

  • They share 39 benchmarks with published results for both. Claude Opus 4.5 scores higher in 2 categories and Gemini 3.8 Flash in 8 categories; 8 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Gemini 3.8 Flash leads 76.9 to 42.6.
  • The biggest single-benchmark swing is ARC-AGI-2: 37.6% for Claude Opus 4.5 and 89.2% for Gemini 3.8 Flash.
  • Gemini 3.8 Flash is cheaper at $0.75 / $3.75 per million input/output tokens, against $5 / $25 for Claude Opus 4.5.
  • Gemini 3.8 Flash accepts more context: 1.05M tokens versus 200K.

Side by side

Claude Opus 4.5 and Gemini 3.8 Flash specifications
Claude Opus 4.5Gemini 3.8 Flash
ProviderAnthropicGoogle
Noometry Index50.561.8
Released2025-11-012026-09-02
WeightsProprietaryProprietary
Context window200K1.05M
Max output64K66K
Input $ / M tokens$5$0.75
Output $ / M tokens$25$3.75
Results tracked6950

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Category by category

Coding Gemini 3.8 Flash leads

Claude Opus 4.5: 54.8 (#27), Gemini 3.8 Flash: 59.2 (#15)

Coding benchmarks
BenchmarkClaude Opus 4.5Gemini 3.8 Flash
LMArena WebDev14941584
WeirdML63.7%84.8%
LMArena Coding15041510
ALE-Bench1,0251,270
SWE-bench Verified76.7%—
DeepSWE—73.8%
FrontierCode—41.2%
SWE-bench Verified (bash only)76.8%—
CursorBench—39.6%
SWE-bench Multilingual70.7%—
FrontierSWE—19.6%
SciCode—56.6%
GSO26.5%—
AlgoTune1.77—

Agentic & Tool Use Claude Opus 4.5 leads

Claude Opus 4.5: 47.3 (#12), Gemini 3.8 Flash: 41.8 (#21)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 4.5Gemini 3.8 Flash
Remote Labor Index3.8%5.8%
Vending-Bench 24,9675,094
Terminal-Bench63.1%—
APEX-Agents—64.3%
Berkeley Function Calling Leaderboard77.5%—
GDPval45.5%—
τ²-bench Airline84%—
τ²-bench Banking24.7%—
τ²-bench Retail79.6%—
τ²-bench Telecom92.3%—
Cybench82%—
DeepResearch Bench54.8%—
OSWorld66.3%—
BALROG43.5%—
GDP.pdf—23.4%
LMArena Search1180—
METR Time Horizons75%—

Reasoning Gemini 3.8 Flash leads

Claude Opus 4.5: 42.6 (#51), Gemini 3.8 Flash: 76.9 (#5)

Reasoning benchmarks
BenchmarkClaude Opus 4.5Gemini 3.8 Flash
ARC-AGI-237.6%89.2%
NYT Connections (extended)52.5%97.4%
ARC-AGI-180%98.5%
Chess Puzzles12%61%
LMArena Hard Prompts14761508
Mystery Game Puzzles22%47%
DTBench89.9%95.7%
LMCA44.5%52.9%
Epoch Capabilities Index150.09156.71
SimpleBench62%—
Kagi LLM Benchmark80.2%—
CritPt—18.3%
EnigmaEval11.9%—
EBR-Bench14.3%—
Surface Evolver Bench—76.9%
ForecastBench60.7—

Math Gemini 3.8 Flash leads

Claude Opus 4.5: 38.6 (#132), Gemini 3.8 Flash: 65.3 (#28)

Math benchmarks
BenchmarkClaude Opus 4.5Gemini 3.8 Flash
FrontierMath (Tiers 1-3)34.4%68.4%
FrontierMath Tier 44.9%22%
OTIS Mock AIME 2024-202586.1%98.9%
ProofBench36%48%
LMArena Math14631528
FrontierMath (Feb 2025 set)20.7%—
FrontierMath Tier 4 (v1)4.2%—

Knowledge Gemini 3.8 Flash leads

Claude Opus 4.5: 56.5 (#44), Gemini 3.8 Flash: 74.8 (#2)

Knowledge benchmarks
BenchmarkClaude Opus 4.5Gemini 3.8 Flash
GPQA Diamond86%95.4%
Humanity's Last Exam25.2%44.5%
SimpleQA Verified45.7%69.7%
LMArena Expert14871524
Vectara Hallucination Rate10.9%—

Multimodal Gemini 3.8 Flash leads

Claude Opus 4.5: 31.4 (#107), Gemini 3.8 Flash: 40.7 (#45)

Multimodal benchmarks
BenchmarkClaude Opus 4.5Gemini 3.8 Flash
Furniture Assembly28.3%31.7%
LMArena Vision—1314
GeoBench75%—
VPCT40%—
Blueprint-Bench 2—38.6%
LMArena Document1462—

Multilingual Gemini 3.8 Flash leads

Claude Opus 4.5: 54.3 (#47), Gemini 3.8 Flash: 58.0 (#5)

Multilingual benchmarks
BenchmarkClaude Opus 4.5Gemini 3.8 Flash
LMArena Non-English14381491
LMArena Chinese14701554
LMArena French14711498
LMArena German14491493
LMArena Japanese14161502
LMArena Korean14241459
LMArena Russian14471515
LMArena Spanish14581485

Instruction Following Too close to call

Claude Opus 4.5: 77.5 (#19), Gemini 3.8 Flash: 78.0 (#13)

Instruction Following benchmarks
BenchmarkClaude Opus 4.5Gemini 3.8 Flash
LMArena Instruction Following14781490

Long Context Too close to call

Claude Opus 4.5: 46.5 (#22), Gemini 3.8 Flash: 46.3 (#24)

Long Context benchmarks
BenchmarkClaude Opus 4.5Gemini 3.8 Flash
LMArena Longer Query14801508
CL-bench21.1%—

Writing & Preference Gemini 3.8 Flash leads

Claude Opus 4.5: 68.1 (#28), Gemini 3.8 Flash: 72.2 (#15)

Writing & Preference benchmarks
BenchmarkClaude Opus 4.5Gemini 3.8 Flash
LMArena Text14511499
LMArena Creative Writing14451492
EQ-Bench Creative Writing16871748
LMArena Multi-Turn14661501

Frequently asked questions

Is Claude Opus 4.5 better than Gemini 3.8 Flash?

Gemini 3.8 Flash is the stronger model overall, scoring 61.8 to 50.5 on the Noometry Index.

Which is cheaper, Claude Opus 4.5 or Gemini 3.8 Flash?

Gemini 3.8 Flash is cheaper. It lists at $0.75 per million input tokens and $3.75 per million output tokens; Claude Opus 4.5 lists at $5 and $25.

Is Claude Opus 4.5 or Gemini 3.8 Flash better for coding?

Gemini 3.8 Flash scores higher on coding benchmarks: 59.2 versus 54.8 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.8 Flash does, with 1.05M tokens against 200K.

How many benchmarks do Claude Opus 4.5 and Gemini 3.8 Flash share?

39 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and Gemini 3.8 Flash has 50.

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