BenchLeader

Claude Opus 4.6 vs Gemini 3.5 Flash

Full profiles: Claude Opus 4.6 (Anthropic) and Gemini 3.5 Flash (Google): every benchmark, price and rank.

Updated · Data from 10 sources

As of 25 Oct 2026, Claude Opus 4.6 (high) and Gemini 3.5 Flash (high) are neck and neck on quality (62.7 vs 63.1 on the BenchLeader Index, inside the ±3.7 margin of error), and Gemini 3.5 Flash (high) costs 3.0× less, which makes it the better buy for most workloads. Claude Opus 4.6 leads in every category we measure both in.

Which to pick for…

The pick's numbers come first. Category scores on the BenchLeader scale (50 is the average model, 15 points one standard deviation). High confidence means a lead of half a standard deviation or more; under one point is called either.

Use casePickWhyConfidence
CodingClaude Opus 4.663 vs 60 category score; Arena WebDev 1546 vs 1499Medium
MathsClaude Opus 4.664 vs 58 category score; Arena Maths 1517 vs 1497Medium
ReasoningClaude Opus 4.666 vs 61 category score; Arena Hard Prompts 1530 vs 1495Medium
Images and other mediaEither67 vs 67 category score; Arena Vision 1316 vs 1308Either
Chat quality (human preference)Claude Opus 4.670 vs 67 on Arena votesMedium
Lowest costGemini 3.5 Flash$3.38 vs $10.00 per 1M blended; agentic coding session $0.126 vs $0.400–
Fastest first answerClaude Opus 4.61.2 s (Claude Opus 4.6 (high)) vs 14.2 s (Gemini 3.5 Flash (high)) to the first answer token–
High volume on a budgetNeither flagshipA smaller model is usually the better fit: Cheapest good LLMs, Fastest LLMs–

Key differences

  • Claude Opus 4.6 (high) and Gemini 3.5 Flash (high) are neck and neck on quality (62.7 vs 63.1, within the ±3.7 margin).
  • Claude Opus 4.6 (high) is stronger in coding, human preference, maths, reasoning.
  • Gemini 3.5 Flash (high) is stronger in agents & tools, composite, instruction following, knowledge, long context.
  • Gemini 3.5 Flash (high) is 3.0× cheaper ($3.38 vs $10.00 per 1M blended).
  • Gemini 3.5 Flash (high) streams 5.7× faster (222 vs 39 tokens per second).

At a glance

SpecClaude Opus 4.6Gemini 3.5 Flash
DeveloperAnthropicGoogle
Released5 Feb 202619 May 2026
Context window (tokens)1,000,0001,048,576
Compared atClaude Opus 4.6 (high)Gemini 3.5 Flash (high)
Open weightsNoNo
Price in / out / cached input per 1M$5.00 / $25.00 / $0.500$1.50 / $9.00 / $0.150

Category by category

Category scores on the BenchLeader scale: 50 is the average evaluated model, 15 points is one standard deviation. A gap under one point is called level.

CategoryClaude Opus 4.6 (high)Gemini 3.5 Flash (high)Leader
Reasoning65.561.3Claude Opus 4.6
Coding62.759.8Claude Opus 4.6
Agents & tools–63.4not comparable
Maths63.558.3Claude Opus 4.6
Knowledge–65.2not comparable
Instruction following–74.3not comparable
Human preference70.066.8Claude Opus 4.6
Multimodal66.666.6level
Long context–61.6not comparable
Composite–65.9not comparable

Where sources disagree

Across the 21 benchmarks both have, Claude Opus 4.6 leads 15, Gemini 3.5 Flash leads 4 and 2 are tied. Independent sources split: Claude Opus 4.6 leads on Arena Text; Gemini 3.5 Flash leads on AA Intelligence Index v4.3.2.

Overall indexClaude Opus 4.6 (high)Gemini 3.5 Flash (high)Leader
BenchLeader Index62.763.1neck and neck
AA Intelligence Index v4.3.226.4†32.6Gemini 3.5 Flash
Arena Text15031477Claude Opus 4.6

Each publisher runs its own tasks, harnesses and effort settings, so their overall verdicts can differ; BenchLeader reconciles them on one scale. † measured at another effort setting of the same model (the publisher did not test the one compared here).

Price, speed and latency

List prices blended at three input tokens per output token. Per-task prices use the token counts on the methodology page; suite cost is what Artificial Analysis paid to run its whole Intelligence Index.

MeasureClaude Opus 4.6 (high)Gemini 3.5 Flash (high)
Blended price per 1M tokens$10.00$3.38
Input / output per 1M$5.00 / $25.00$1.50 / $9.00
Cached input per 1M$0.500$0.150
Price per task: chat reply$0.0095$0.0033
Price per task: summarize a 30-page report$0.075$0.023
Price per task: code edit$0.068$0.022
Price per task: agentic coding session$0.400$0.126
Price per task: structured extraction$0.015$0.0048
Cost to run a full benchmark suite–$3.69
Output speed39 tok/s222 tok/s
Time to first answer1.2 s14.2 s
Time to a complete answer–16.4 s

Each model is compared at its best-ranked reasoning-effort setting. Claude Opus 4.6 (high) scores 62.7 and takes 1 s to its first answer token; Claude Opus 4.6 (thinking) scores 62.5 in 1 s, Claude Opus 4.6 scores 62.5 in 1 s. Gemini 3.5 Flash (high) scores 63.1 and takes 14 s to its first answer token; Gemini 3.5 Flash (medium) scores 62.8 in 12 s, Gemini 3.5 Flash (minimal) scores 56.4 in 1 s. Higher effort means more thinking before the answer: better scores, longer waits and more tokens billed. How reasoning effort changes scores and cost.

Every benchmark

141 benchmarks, grouped by category; each name links to the board and its leaders. † measured at another effort setting of the same model, shown for reference and not counted as a win.

MetricPublisherClaude Opus 4.6 (high)Gemini 3.5 Flash (high)
BenchLeader IndexBenchLeader62.763.1
Coding scoreBenchLeader62.759.8
Human preference scoreBenchLeader70.066.8
Maths scoreBenchLeader63.558.3
Multimodal scoreBenchLeader66.666.6
Reasoning scoreBenchLeader65.561.3
Agents & tools scoreBenchLeader–63.4
Composite scoreBenchLeader–65.9
Instruction following scoreBenchLeader–74.3
Knowledge scoreBenchLeader–65.2
Long context scoreBenchLeader–61.6
Blended price $/MBenchLeader$10.00$3.38
Output speedBenchLeader39 tok/s222 tok/s
Time to first answerBenchLeader1.2 s14.2 s
Context windowBenchLeader1,000,000 tokens1,048,576 tokens
Reasoning
GPQA DiamondEpoch AI Benchmarking Hub90.5%†92.8%
Humanity's Last ExamScale AI / CAIS19.0%†–
SimpleBenchSimpleBench67.6%†76.7%†
Arena Hard PromptsArena (LMArena)15301495
LiveBench 1.0 ReasoningLiveBench88.7%82.0%
GPQA Diamond (AA)Artificial Analysis89.6%†92.2%
Humanity's Last Exam (AA)Artificial Analysis39.9%†42.7%
GPQA Diamond (Vals)Vals AI89.7%†92.7%
EnigmaEvalScale AI SEAL–25.4%
Kagi LLM BenchmarkKagi LLM Benchmark72.4%†–
ARC-AGI-1ARC Prize94.0%92.5%
ARC-AGI-2ARC Prize69.2%72.1%
ARC-AGI-3ARC Prize0.5%†–
CritPtArtificial Analysis12.6%†13.1%
Chess PuzzlesEpoch AI Benchmarking Hub21.0%†45.0%
Mystery Game PuzzlesEpoch AI Benchmarking Hub15.0%†32.0%
CL-benchEpoch AI Benchmarking Hub20.7%†–
CL-bench LifeEpoch AI Benchmarking Hub17.0%–
LMCAEpoch AI Benchmarking Hub55.8%†47.1%
DTBenchEpoch AI Benchmarking Hub91.2%†94.7%
ForecastBenchForecastBench63.4%†64.3%†
Coding
SWE-bench Verified (Epoch)Epoch AI Benchmarking Hub78.7%†79.3%
SciCodeSciCode–53.9%
WeirdMLWeirdML78.0%62.6%
FrontierCodeCognition26.6%†–
Show all 141 benchmarks
MetricPublisherClaude Opus 4.6 (high)Gemini 3.5 Flash (high)
Coding
GSO-BenchGSO-Bench41.2%–
Arena CodingArena (LMArena)15471508
Arena WebDevArena (LMArena)15461499
LiveBench 1.0 CodingLiveBench78.2%78.2%
LiveCodeBenchVals AI84.7%†87.6%
SWE-bench (Vals)Vals AI78.2%†78.8%
SWE-Bench ProScale AI SEAL51.9%†–
SWE-bench Verified (bash only)SWE-bench75.6%†–
SWE-bench Verified (any scaffold)SWE-bench75.6%†–
Code MigrationVals AI–26.8%
ProgramBenchVals AI–0.0%
Vibe Code Bench v1.1Vals AI57.6%†48.7%
SWE-Bench Pro (private)Scale AI SEAL51.9%†–
SWE Atlas: Codebase QnAScale AI SEAL33.3%†–
SWE Atlas: RefactoringScale AI SEAL35.6%†–
SWE Atlas: Test WritingScale AI SEAL36.7%†–
Surface Evolver BenchEpoch AI Benchmarking Hub–58.1%†
DeepSWE v1.1Epoch AI Benchmarking Hub–36.1%
ALE-BenchEpoch AI Benchmarking Hub996.5†911.0
AlgoTuneAlgoTune1.5–
Terminal-Bench 4.0 (AA)Artificial Analysis–6.6%
Terminal-Bench 2.1 (AA)Artificial Analysis–78.7%
Agents & tools
Terminal-BenchTerminal-Bench79.8%†–
CybenchCybench93.0%†–
Remote Labor IndexScale AI / CAIS4.2%†–
APEX-AgentsMercor46.3%†27.5%†
LiveBench Agentic CodingLiveBench49.0%49.0%
Terminal-Bench HardArtificial Analysis46.2%†40.9%
τ²-Bench Telecom (AA)Artificial Analysis92.1%†95.3%
Terminal-Bench 2.1 (Vals)Vals AI–74.2%
MCP AtlasScale AI SEAL76.8%†83.6%
HiL-BenchScale AI SEAL38.3%†27.7%†
τ³-bench Bankingτ²-bench27.3%†–
τ³-Banking (AA)Artificial Analysis–32.2%
ITBench SRE (AA)Artificial Analysis–40.4%
Analyst Agent (AA)Artificial Analysis–45.0%
APEX-Agents (AA)Artificial Analysis33.0%†47.0%
Finance Agent v2Vals AI–57.9%
Harvey's Legal Agent Benchmark v1Vals AI–2.5%
Legal Research BenchVals AI–30.8%
SkillsBenchVals AI–52.7%
Tax Agent BenchVals AI–21.6%
Terminal-Bench 2.0 (Vals)Vals AI58.4%†67.4%
Terminal-Bench 4.0 (Vals)Vals AI–6.1%
Terminal-Bench ScienceVals AI–5.7%
Web Search IndexVals AI–37.0%
DeepResearch BenchDeepResearch Bench55.3%–
METR Time HorizonsMETR78.9%†–
GBAEvalEpoch AI Benchmarking Hub44.1%†6.7%†
Vending-Bench 2Andon Labs8017.6†5396.4†
AutomationBenchArtificial Analysis–42.1%
GDP.pdf (AA)Artificial Analysis–19.8%
EnterpriseOps-GymArtificial Analysis–50.1%
AA-Briefcase v1.1Artificial Analysis–874
FACTS SearchGoogle–64.3%†
Maths
FrontierMath Tiers 1–3Epoch AI Benchmarking Hub66.0%†62.8%
FrontierMath Tier 4Epoch AI Benchmarking Hub26.8%†26.8%
OTIS Mock AIMEEpoch AI Benchmarking Hub94.4%†95.6%
ProofBenchVals AI50.0%†31.0%
LiveBench MathematicsLiveBench89.3%88.2%
AIME (Vals)Vals AI95.6%†–
AIME 2026MathArena96.7%95.0%†
HMMT February 2026MathArena96.2%95.5%†
USAMO 2026MathArena47.0%–
MathArena ApexMathArena34.5%32.3%†
Arena MathsArena (LMArena)15171497
Knowledge
SimpleQA VerifiedEpoch AI Benchmarking Hub47.0%†66.2%
LiveBench 1.0 Data AnalysisLiveBench69.9%64.9%
AA-OmniscienceArtificial Analysis13.7†21.2
MMLU-ProVals AI89.1%†89.5%
LegalBenchVals AI85.3%†83.6%
CorpFinVals AI67.0%†64.7%
TaxEvalVals AI76.0%†74.4%
MedQAVals AI95.4%†–
PRBench FinanceScale AI SEAL53.3%†–
PRBench LegalScale AI SEAL52.3%†–
MultiNRCScale AI SEAL57.1%†–
CaseLaw v2Vals AI62.1%†–
Excel Modeling BenchmarkVals AI–63.5%
MedCodeVals AI48.2%†55.8%
MedScribeVals AI86.7%†76.6%
Public Benefits Bench v1.1Vals AI–59.5%
DrugDiscoveryBenchScale AI SEAL27.7%†50.0%
EBR-benchEpoch AI Benchmarking Hub12.7%†4.8%
GDP.pdfEpoch AI Benchmarking Hub–14.0%†
AA-Omniscience: accuracyArtificial Analysis47.0%†51.4%
AA-Omniscience: non-hallucinationArtificial Analysis37.2%†37.8%
Global-MMLU-Lite (AA)Artificial Analysis92.2%†–
Instruction following
LiveBench LanguageLiveBench83.3%84.6%
LiveBench Instruction FollowingLiveBench63.3%75.6%
IFBenchArtificial Analysis53.1%†76.3%
MultiChallengeScale AI SEAL37.1%†–
TutorBenchScale AI SEAL53.7%†–
Arena Instruction FollowingArena (LMArena)15111465
Human preference
Arena TextArena (LMArena)15031477
EQ-Bench 4EQ-Bench1213†1081†
Arena Creative WritingArena (LMArena)15001464
Arena Multi-turnArena (LMArena)15161480
Arena Longer QueriesArena (LMArena)15211482
Multimodal
Arena VisionArena (LMArena)13161308
MMMU-ProArtificial Analysis75.4%†84.3%
VISTAScale AI SEAL46.1%†–
MMMU-Pro (Vals)Vals AI83.9%†88.3%
MortgageTaxVals AI68.5%†68.1%
SAGEVals AI51.6%†49.9%
VTBScale AI SEAL27.5%†–
Blueprint-Bench 2Epoch AI Benchmarking Hub–33.6%†
Long context
AA-LCRArtificial Analysis78.0%†73.3%
Arena DocumentArena (LMArena)14951453
MLCRArtificial Analysis–10.0%
Composite
Epoch Capabilities IndexEpoch AI Benchmarking Hub155.7†154.9†
LiveBench 1.0LiveBench74.5%74.6%
AA Intelligence Index v4.3.2Artificial Analysis31.9†32.6
Vals Multimodal IndexVals AI–62.9%
Safety & honesty
FORTRESSScale AI SEAL13.0%†–
MASKScale AI SEAL85.4%†–

Data as of 2026-10-25. Best configuration of each model; every score links to its source on the model pages.

What changed

  • Gemini 3.5 Flash (high): 1 new result (Harvey's Legal Agent Benchmark v1).
  • Gemini 3.5 Flash (high): 1 score revision.
  • Claude Opus 4.6 (high): BenchLeader Index 60.4 → 62.9.
  • Gemini 3.5 Flash (high): BenchLeader Index 62.5 → 63.2.
  • Claude Opus 4.6 (high): 1 new result (USAMO 2026).
  • Gemini 3.5 Flash (high): 3 new results (GDPval-AA v2.1, AA-Omniscience: accuracy, AA-Omniscience: non-hallucination).
  • Gemini 3.5 Flash (high): 1 score revision.
  • Gemini 3.5 Flash (high): 2 score revisions.
  • Gemini 3.5 Flash (high): BenchLeader Index 63.0 → 62.5.
  • Gemini 3.5 Flash (high): 1 new result (DrugDiscoveryBench).

Rankings: Best LLM overall · Best LLM for agents · Best cheap LLMs

Claude Opus 4.6 vs Gemini 3.5 Flash: questions

Is Claude Opus 4.6 better than Gemini 3.5 Flash?
Claude Opus 4.6 (high) and Gemini 3.5 Flash (high) are neck and neck on quality (62.7 vs 63.1, within the ±3.7 margin). The BenchLeader Index combines every independent quality benchmark; the two are within the margin of error as of 2026-10-25, so check the category scores for your use.
Which is cheaper, Claude Opus 4.6 or Gemini 3.5 Flash, and will that change?
Gemini 3.5 Flash is cheaper today: $3.38 against $10.00 per million tokens, blended at three input tokens per output token. No price change has been announced for either.
Is Claude Opus 4.6 better than Gemini 3.5 Flash for coding?
Claude Opus 4.6 scores higher in coding (63 vs 60 on the category index, where 50 is average). On Arena WebDev, the top shared coding benchmark, it is 1546 for Claude Opus 4.6 against 1499 for Gemini 3.5 Flash.
Which is better for long documents?
Both take about 1M tokens: Claude Opus 4.6 1,000,000, Gemini 3.5 Flash 1,048,576.
Which has lower latency?
Claude Opus 4.6 (high) answers first: 1.2 s against 14.2 s to the first answer token, as Artificial Analysis measures it. Reasoning effort drives most of this: a higher setting thinks longer before it answers.
Which is faster, Claude Opus 4.6 or Gemini 3.5 Flash?
Gemini 3.5 Flash streams faster: 222 against 39 output tokens per second.
Do independent benchmarks agree on Claude Opus 4.6 vs Gemini 3.5 Flash?
Across the 21 benchmarks both have, Claude Opus 4.6 leads 15, Gemini 3.5 Flash leads 4 and 2 are tied. Independent sources split: Claude Opus 4.6 leads on Arena Text; Gemini 3.5 Flash leads on AA Intelligence Index v4.3.2.
When was Gemini 3.5 Flash released?
Gemini 3.5 Flash was released on 19 May 2026.