Model comparison

Claude Opus 5 vs Gemini 3.8 Flash

Claude Opus 5 is the stronger model overall, scoring 67.8 to 61.8 on the Noometry Index. Gemini 3.8 Flash costs 6.7× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.

Last verified . 47 shared benchmarks.

Claude Opus 5 Anthropic

67.8

Rank #4 Confirmed

Gemini 3.8 Flash Google

61.8

Rank #11 Confirmed

Summary

  • They share 47 benchmarks with published results for both. Claude Opus 5 scores higher in 9 categories and Gemini 3.8 Flash in 1 category; 7 gaps are clear of the uncertainty.
  • The widest gap is in math, where Claude Opus 5 leads 86.2 to 65.3.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 73.2% for Claude Opus 5 and 22% 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 5.
  • Gemini 3.8 Flash accepts more context: 1.05M tokens versus 1M.

Side by side

Claude Opus 5 and Gemini 3.8 Flash specifications
Claude Opus 5Gemini 3.8 Flash
ProviderAnthropicGoogle
Noometry Index67.861.8
Released2026-07-242026-09-02
WeightsProprietaryProprietary
Context window1M1.05M
Max output128K66K
Input $ / M tokens$5$0.75
Output $ / M tokens$25$3.75
Results tracked5750

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

Category by category

Coding Claude Opus 5 leads

Claude Opus 5: 67.5 (#5), Gemini 3.8 Flash: 59.2 (#15)

Coding benchmarks
BenchmarkClaude Opus 5Gemini 3.8 Flash
DeepSWE73.6%73.8%
FrontierCode53.4%41.2%
CursorBench46.6%39.6%
LMArena WebDev16911584
FrontierSWE52%19.6%
SciCode56.4%56.6%
WeirdML91.8%84.8%
LMArena Coding15341510
ALE-Bench2,1651,270

Agentic & Tool Use Claude Opus 5 leads

Claude Opus 5: 55.6 (#1), Gemini 3.8 Flash: 41.8 (#21)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 5Gemini 3.8 Flash
APEX-Agents65.8%64.3%
GDP.pdf24%23.4%
Vending-Bench 211,1825,094
OSWorld 2.031.4%—
Remote Labor Index—5.8%
τ²-bench Banking48.7%—
PostTrainBench35%—
BALROG63.4%—
GBAEval79.6%—

Reasoning Too close to call

Claude Opus 5: 77.2 (#4), Gemini 3.8 Flash: 76.9 (#5)

Reasoning benchmarks
BenchmarkClaude Opus 5Gemini 3.8 Flash
ARC-AGI-290.4%89.2%
NYT Connections (extended)94.3%97.4%
ARC-AGI-197.5%98.5%
CritPt29.1%18.3%
Chess Puzzles42%61%
LMArena Hard Prompts15261508
Mystery Game Puzzles59%47%
DTBench97.9%95.7%
LMCA64.5%52.9%
Epoch Capabilities Index162.78156.71
SimpleBench80.6%—
EBR-Bench45.7%—
Surface Evolver Bench—76.9%
Bench to the Future 30.12—

Math Claude Opus 5 leads

Claude Opus 5: 86.2 (#8), Gemini 3.8 Flash: 65.3 (#28)

Math benchmarks
BenchmarkClaude Opus 5Gemini 3.8 Flash
FrontierMath (Tiers 1-3)85.6%68.4%
FrontierMath Tier 473.2%22%
OTIS Mock AIME 2024-202598.9%98.9%
ProofBench99%48%
LMArena Math15311528

Knowledge Gemini 3.8 Flash leads

Claude Opus 5: 66.8 (#9), Gemini 3.8 Flash: 74.8 (#2)

Knowledge benchmarks
BenchmarkClaude Opus 5Gemini 3.8 Flash
GPQA Diamond93.9%95.4%
SimpleQA Verified59.9%69.7%
LMArena Expert15571524
Humanity's Last Exam—44.5%

Multimodal Claude Opus 5 leads

Claude Opus 5: 50.8 (#8), Gemini 3.8 Flash: 40.7 (#45)

Multimodal benchmarks
BenchmarkClaude Opus 5Gemini 3.8 Flash
LMArena Vision13191314
Blueprint-Bench 230.4%38.6%
Furniture Assembly60.8%31.7%
LMArena Document1516—

Multilingual Too close to call

Claude Opus 5: 58.8 (#4), Gemini 3.8 Flash: 58.0 (#5)

Multilingual benchmarks
BenchmarkClaude Opus 5Gemini 3.8 Flash
LMArena Non-English15011491
LMArena Chinese15741554
LMArena French15191498
LMArena German15241493
LMArena Japanese15161502
LMArena Korean15211459
LMArena Russian15071515
LMArena Spanish15191485

Instruction Following Claude Opus 5 leads

Claude Opus 5: 79.2 (#7), Gemini 3.8 Flash: 78.0 (#13)

Instruction Following benchmarks
BenchmarkClaude Opus 5Gemini 3.8 Flash
LMArena Instruction Following15171490

Long Context Too close to call

Claude Opus 5: 46.5 (#21), Gemini 3.8 Flash: 46.3 (#24)

Long Context benchmarks
BenchmarkClaude Opus 5Gemini 3.8 Flash
LMArena Longer Query15151508

Writing & Preference Claude Opus 5 leads

Claude Opus 5: 79.2 (#1), Gemini 3.8 Flash: 72.2 (#15)

Writing & Preference benchmarks
BenchmarkClaude Opus 5Gemini 3.8 Flash
LMArena Text15071499
LMArena Creative Writing14911492
EQ-Bench Creative Writing21331748
LMArena Multi-Turn14991501
EQ-Bench 41385—

Frequently asked questions

Is Claude Opus 5 better than Gemini 3.8 Flash?

Claude Opus 5 is the stronger model overall, scoring 67.8 to 61.8 on the Noometry Index. Gemini 3.8 Flash costs 6.7× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 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 5 lists at $5 and $25.

Is Claude Opus 5 or Gemini 3.8 Flash better for coding?

Claude Opus 5 scores higher on coding benchmarks: 67.5 versus 59.2 in the Noometry coding category.

Which has the bigger context window?

Gemini 3.8 Flash does, with 1.05M tokens against 1M.

How many benchmarks do Claude Opus 5 and Gemini 3.8 Flash share?

47 benchmarks have published results for both models. Claude Opus 5 has 57 scored results on Noometry and Gemini 3.8 Flash has 50.

Related comparisons

Go deeper