BenchLeader

Claude Opus 5 vs Gemini 3.8 Flash

Full profiles: Claude Opus 5 (Anthropic) and Gemini 3.8 Flash (Google): every benchmark, price and rank.

Updated · Data from 11 sources

As of 24 Oct 2026, Claude Opus 5 (max) and Gemini 3.8 Flash (high) are neck and neck on quality (68.8 vs 64.4 on the BenchLeader Index, inside the ±4.8 margin of error), and Gemini 3.8 Flash (high) costs 6.7× less, which makes it the better buy for most workloads. Gemini 3.8 Flash (high)'s current price runs until 31 Dec 2026; from 1 Jan 2027 Gemini 3.8 Flash (high) costs 3.3× less ($3.00 vs $10.00 per 1M blended); on use case, pick Claude Opus 5 for agents & tools (64 vs 51), Gemini 3.8 Flash for long context (66 vs 65).

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 570 vs 64 category score; Arena WebDev 1690 vs 1585Medium
Agents & tool useClaude Opus 564 vs 51 category score; Terminal-Bench 51.8% vs 19.1%High
MathsClaude Opus 571 vs 62 category score; FrontierMath Tiers 1–3 85.6% vs 68.4%High
ReasoningClaude Opus 574 vs 68 category score; ARC-AGI-2 90.4% vs 89.2%Medium
KnowledgeClaude Opus 572 vs 68 category score; AA-Omniscience 37.1 vs 29.6Medium
Long documentsGemini 3.8 Flash66 vs 65 category score; AA-LCR 81.3% vs 79.3%Medium
Images and other mediaEither68 vs 68 category score; MMMU-Pro 84.7% vs 85.6%Either
Chat quality (human preference)Either69 vs 69 on Arena votesEither
Lowest costGemini 3.8 Flash$1.50 vs $10.00 per 1M blended; agentic coding session $0.060 vs $0.400; from 1 Jan 2027: $3.00 vs $10.00–
Fastest first answerEither20.2 s (Claude Opus 5 (max)) vs 25.1 s (Gemini 3.8 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 5 (max) and Gemini 3.8 Flash (high) are neck and neck on quality (68.8 vs 64.4, within the ±4.8 margin).
  • Claude Opus 5 (max) is stronger in agents & tools, coding, composite, knowledge, maths, multimodal, reasoning.
  • Gemini 3.8 Flash (high) is stronger in human preference, long context.
  • Gemini 3.8 Flash (high) is 6.7× cheaper ($1.50 vs $10.00 per 1M blended) until 31 Dec 2026, then $3.00 vs $10.00 from 1 Jan 2027.
  • Gemini 3.8 Flash (high) streams 2.5× faster (141 vs 57 tokens per second).

At a glance

SpecClaude Opus 5Gemini 3.8 Flash
DeveloperAnthropicGoogle
Released24 Jul 20262 Sept 2026
Context window (tokens)1,000,0001,048,576
Compared atClaude Opus 5 (max)Gemini 3.8 Flash (high)
Open weightsNoNo
Price in / out / cached input per 1M$5.00 / $25.00 / $0.500$0.750 / $3.75 / $0.075
Announced price changeNone announced$1.50 / $7.50 from 1 Jan 2027

Limits, availability and announced prices from the vendors' own pages: ai.google.dev pricing (checked 20 Oct 2026). Everything else is from the day's data.

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 5 (max)Gemini 3.8 Flash (high)Leader
Reasoning74.168.2Claude Opus 5
Coding70.263.5Claude Opus 5
Agents & tools64.150.9Claude Opus 5
Maths70.662.4Claude Opus 5
Knowledge71.668.4Claude Opus 5
Human preference68.569.1level
Multimodal67.967.7level
Long context64.765.7Gemini 3.8 Flash
Composite86.375.3Claude Opus 5

Where sources disagree

Across the 53 benchmarks both have, Claude Opus 5 leads 34, Gemini 3.8 Flash leads 18 and 1 is a tie. Independent sources split: Claude Opus 5 leads on AA Intelligence Index v4.3.2; Gemini 3.8 Flash leads on Arena Text.

Overall indexClaude Opus 5 (max)Gemini 3.8 Flash (high)Leader
BenchLeader Index68.864.4neck and neck
AA Intelligence Index v4.3.250.840.9Claude Opus 5
Arena Text14911496Gemini 3.8 Flash

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 5 (max)Gemini 3.8 Flash (high)
Blended price per 1M tokens, until 31 Dec 2026$10.00$1.50
Input / output per 1M$5.00 / $25.00$0.750 / $3.75
Blended price per 1M from 1 Jan 2027$10.00$3.00
Input / output per 1M from 1 Jan 2027$5.00 / $25.00$1.50 / $7.50
Cached input per 1M$0.500$0.075
Price per task: chat reply$0.0095$0.0014
Price per task: summarize a 30-page report$0.075$0.011
Price per task: code edit$0.068$0.010
Price per task: agentic coding session$0.400$0.060
Price per task: structured extraction$0.015$0.0023
Cost to run a full benchmark suite$5.86$1.24
Output speed57 tok/s141 tok/s
Time to first answer20.2 s25.1 s
Time to a complete answer29.1 s28.7 s

Per token is not per task: on Artificial Analysis' full suite Claude Opus 5 (max) cost $5.86 and Gemini 3.8 Flash (high) $1.24, because Gemini 3.8 Flash (high) used about 1.4× as many tokens for the same work, which a per-token price hides.

Each model is compared at its best-ranked reasoning-effort setting. Claude Opus 5 (max) scores 68.8 and takes 20 s to its first answer token; Claude Opus 5 (high) scores 67.9 in 9 s, Claude Opus 5 (xhigh) scores 67.4 in 24 s. Gemini 3.8 Flash (high) scores 64.4 and takes 25 s to its first answer token; Gemini 3.8 Flash (medium) scores 64.4 in 3 s, Gemini 3.8 Flash (low) scores 61.0 in 3 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

153 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 5 (max)Gemini 3.8 Flash (high)
BenchLeader IndexBenchLeader68.864.4
Agents & tools scoreBenchLeader64.150.9
Coding scoreBenchLeader70.263.5
Composite scoreBenchLeader86.375.3
Human preference scoreBenchLeader68.569.1
Knowledge scoreBenchLeader71.668.4
Long context scoreBenchLeader64.765.7
Maths scoreBenchLeader70.662.4
Multimodal scoreBenchLeader67.967.7
Reasoning scoreBenchLeader74.168.2
Blended price $/MBenchLeader$10.00$1.50
Output speedBenchLeader57 tok/s141 tok/s
Time to first answerBenchLeader20.2 s25.1 s
Context windowBenchLeader1,000,000 tokens1,048,576 tokens
Reasoning
GPQA DiamondEpoch AI Benchmarking Hub93.9%95.4%
Humanity's Last ExamScale AI / CAIS–44.5%†
SimpleBenchSimpleBench80.6%†–
Arena Hard PromptsArena (LMArena)15151517
LiveBench 2.0 ReasoningLiveBench91.2%†89.3%†
LiveBench 1.0 ReasoningLiveBench91.2%89.3%
GPQA Diamond (AA)Artificial Analysis93.2%95.3%
Humanity's Last Exam (AA)Artificial Analysis54.9%47.8%
GPQA Diamond (Vals)Vals AI93.4%†94.4%
ARC-AGI-1ARC Prize97.5%98.5%
ARC-AGI-2ARC Prize90.4%89.2%
ARC-AGI-3ARC Prize30.2%†35.0%
CritPtArtificial Analysis29.1%18.3%
MysteryMechanismVals AI37.4%†36.5%
Chess PuzzlesEpoch AI Benchmarking Hub43.0%58.0%
Mystery Game PuzzlesEpoch AI Benchmarking Hub59.0%47.0%
LMCAEpoch AI Benchmarking Hub63.3%51.5%†
DTBenchEpoch AI Benchmarking Hub97.6%95.7%†
ForecastBenchForecastBench66.5%–
BTF-3Epoch AI Benchmarking Hub12.0%†–
Coding
SciCodeSciCode56.4%56.6%
WeirdMLWeirdML91.8%84.8%
FrontierCodeCognition53.4%41.2%†
Arena CodingArena (LMArena)15281528
Arena WebDevArena (LMArena)16901585
Show all 153 benchmarks
MetricPublisherClaude Opus 5 (max)Gemini 3.8 Flash (high)
Coding
LiveBench 2.0 CodingLiveBench90.8%†82.2%†
LiveBench 1.0 CodingLiveBench81.5%72.5%
LiveCodeBenchVals AI89.0%†89.5%
IOIVals AI84.3%†56.9%
SWE-bench (Vals)Vals AI97.0%†80.0%
Code MigrationVals AI57.5%†36.5%
Code Migration v1.1Vals AI–38.6%
ProgramBenchVals AI3.0%†1.0%
SWE-bench MultimodalVals AI–40.8%
Vibe Code Bench 1-100Vals AI28.5%†18.8%
Vibe Code Bench v1.1Vals AI88.4%†78.7%
SWE Atlas: Codebase QnAScale AI SEAL63.2%†47.0%†
SWE Atlas: RefactoringScale AI SEAL–44.8%†
SWE Atlas: Test WritingScale AI SEAL62.2%†53.7%†
Surface Evolver BenchEpoch AI Benchmarking Hub–76.9%
DeepSWE v1.1Epoch AI Benchmarking Hub73.7%73.8%
CursorBenchCursor46.6%39.6%
ALE-BenchEpoch AI Benchmarking Hub2164.6†1269.7
FrontierSWEEpoch AI Benchmarking Hub52.0%19.6%
Terminal-Bench 4.0 (AA)Artificial Analysis49.0%19.7%
Terminal-Bench 2.1 (AA)Artificial Analysis89.1%87.6%
Startrise FrontendStartrise82.3%†64.6%†
FrontierCode 1.1 (AA)Artificial Analysis–36.4%
Agents & tools
Terminal-BenchTerminal-Bench51.8%19.1%
OSWorld-Verified 2.0OSWorld31.4%–
Remote Labor IndexScale AI / CAIS–5.8%†
APEX-AgentsMercor65.8%64.3%†
Arena AgentArena (LMArena)8.13.6
LiveBench Long AgenticLiveBench62.1%†30.1%†
LiveBench BrowserLiveBench84.0%†64.0%†
LiveBench Agentic CodingLiveBench65.2%54.2%
Terminal-Bench 2.1 (Vals)Vals AI84.6%†81.3%
MCP AtlasScale AI SEAL85.8%†–
HiL-BenchScale AI SEAL57.0%†41.5%†
τ³-bench Bankingτ²-bench48.7%–
GDPval-AA v2.1Artificial Analysis–46.8%
τ³-Banking (AA)Artificial Analysis42.1%45.0%
ITBench SRE (AA)Artificial Analysis–52.5%
Analyst Agent (AA)Artificial Analysis53.8%46.3%
CUA-benchVals AI9.0%4.2%
CyberBenchVals AI65.4%†43.8%
Finance Agent v2Vals AI58.6%†61.4%
Finance Agent v2.1Vals AI–65.8%
Harvey's Legal Agent Benchmark v1.1Vals AI–12.1%
Harvey's Legal Agent Benchmark v1Vals AI6.7%†10.0%
Legal Research BenchVals AI55.3%†38.9%
SkillsBenchVals AI60.4%†58.0%
SREBenchVals AI12.2%†11.1%
Tax Agent BenchVals AI45.5%†32.1%
Terminal-Bench 4.0 (Vals)Vals AI53.5%†19.7%
Terminal-Bench ScienceVals AI27.1%†8.6%
Time Horizon Index: KSPVals AI18.8%†18.8%
Arena SearchArena (LMArena)1214†–
BALROGBALROG63.4%–
PostTrainBenchEpoch AI Benchmarking Hub35.0%†–
GBAEvalEpoch AI Benchmarking Hub79.6%†–
Vending-Bench 2Andon Labs11181.9†5093.8†
AutomationBenchArtificial Analysis56.6%59.9%
GDP.pdf (AA)Artificial Analysis21.6%21.0%
Harvey LAB-AA v1.1Harvey–0.0%
EnterpriseOps-GymArtificial Analysis47.5%–
AA-Briefcase v1.1Artificial Analysis16571202
Terminal-Bench-Science 0.1 (AA)Artificial Analysis28.6%10.0%
CWE-Bench (AA)Artificial Analysis–52.5%
DeepSec-Bench (AA)Artificial Analysis25.9%14.5%
CyberGym end-to-end (AA)Artificial Analysis–8.4%
FACTS SearchGoogle85.3%†76.3%†
Maths
FrontierMath Tiers 1–3Epoch AI Benchmarking Hub85.6%68.4%
FrontierMath Tier 4Epoch AI Benchmarking Hub73.2%21.9%
OTIS Mock AIMEEpoch AI Benchmarking Hub98.9%98.9%
ProofBenchVals AI99.0%48.0%†
LiveBench MathematicsLiveBench95.7%91.6%
Arena MathsArena (LMArena)15171526
Knowledge
SimpleQA VerifiedEpoch AI Benchmarking Hub59.9%69.7%
LiveBench 2.0 Data AnalysisLiveBench74.6%†54.0%†
LiveBench ResearchLiveBench88.9%†79.1%†
LiveBench 1.0 Data AnalysisLiveBench74.5%54.0%
AA-OmniscienceArtificial Analysis37.129.6
MMLU-ProVals AI91.6%†90.2%
LegalBenchVals AI87.0%†87.0%
CorpFinVals AI73.2%†–
TaxEvalVals AI75.1%†74.5%
PRBench FinanceScale AI SEAL–49.5%†
PRBench LegalScale AI SEAL–48.9%†
BioMysteryBenchVals AI79.3%†62.2%
Excel Modeling BenchmarkVals AI73.6%†72.2%
Excel Modeling Benchmark v1.1Vals AI–72.9%
MedCodeVals AI63.6%†48.1%
MedScribeVals AI91.0%†84.5%
Public Benefits Bench v1.1Vals AI76.9%†65.3%
DrugDiscoveryBenchScale AI SEAL53.7%–
EBR-benchEpoch AI Benchmarking Hub45.7%–
GDP.pdfEpoch AI Benchmarking Hub24.0%23.2%
AA-Omniscience: accuracyArtificial Analysis60.9%54.6%
AA-Omniscience: non-hallucinationArtificial Analysis39.2%44.8%
Instruction following
LiveBench LanguageLiveBench88.7%87.8%
LiveBench Instruction FollowingLiveBench63.8%81.4%
Arena Instruction FollowingArena (LMArena)14951490
Human preference
Arena TextArena (LMArena)14911496
EQ-Bench 4EQ-Bench1385†–
Arena Creative WritingArena (LMArena)14741485
Arena Multi-turnArena (LMArena)14871504
Arena Longer QueriesArena (LMArena)15031510
Multimodal
Arena VisionArena (LMArena)1320†1315
LiveBench DesignLiveBench83.0%†72.7%†
MMMU-ProArtificial Analysis84.7%85.6%
MMMU-Pro (Vals)Vals AI89.9%†89.1%
MortgageTaxVals AI72.1%†65.3%
SAGEVals AI49.4%†35.1%
AudioMCScale AI SEAL–60.4%
AudioMC (text output)Scale AI SEAL–60.4%
Blueprint-Bench 2Epoch AI Benchmarking Hub30.4%†38.6%†
AA-3DArtificial Analysis–969
Long context
AA-LCRArtificial Analysis79.3%81.3%
Arena DocumentArena (LMArena)1490†–
MLCRArtificial Analysis11.1%10.6%
Composite
Epoch Capabilities IndexEpoch AI Benchmarking Hub163.9†157.4†
LiveBench 2.0LiveBench82.1%†67.3%†
LiveBench 1.0LiveBench80.1%75.8%
AA Intelligence Index v4.3.2Artificial Analysis50.840.9
Vals IndexVals AI–56.0
Vals Finance IndexVals AI–60.5%
Vals RSI IndexVals AI33.0%19.9%
Vals Science IndexVals AI47.9%†35.8%
Vals Multimodal IndexVals AI73.9%†–
Vals Router IndexVals AI–56.0%†
AA Cyber IndexArtificial Analysis–25.1
Safety & honesty
FORTRESSScale AI SEAL16.8%†–

Data as of 2026-10-24. Best configuration of each model; every score links to its source on the model pages.

What changed

  • Gemini 3.8 Flash: list price moves to $1.50 / $7.50 per 1M input / output tokens (announced).
  • Claude Opus 5 (max): 1 new result (Vals RSI Index).
  • Gemini 3.8 Flash (high): 8 new results (Code Migration v1.1, Excel Modeling Benchmark v1.1, Finance Agent v2.1…).
  • Claude Opus 5 (max): 1 score revision.
  • Gemini 3.8 Flash (high): 1 score revision.
  • Claude Opus 5 (max): 1 new result (ForecastBench); 1 score revision.
  • Gemini 3.8 Flash (high): 3 score revisions.
  • Claude Opus 5 (max): BenchLeader Index 68.3 → 68.9.
  • Gemini 3.8 Flash (high): BenchLeader Index 63.7 → 64.5.
  • Claude Opus 5 (max): 4 new results (GDPval-AA v2.1, AA-Omniscience: accuracy, AA-Omniscience: non-hallucination…).

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

Claude Opus 5 vs Gemini 3.8 Flash: questions

Is Claude Opus 5 better than Gemini 3.8 Flash?
Claude Opus 5 (max) and Gemini 3.8 Flash (high) are neck and neck on quality (68.8 vs 64.4, within the ±4.8 margin). The BenchLeader Index combines every independent quality benchmark; the two are within the margin of error as of 2026-10-24, so check the category scores for your use.
Which is cheaper, Claude Opus 5 or Gemini 3.8 Flash, and will that change?
Gemini 3.8 Flash is cheaper today: $1.50 against $10.00 per million tokens, blended at three input tokens per output token. Yes, that changes: Gemini 3.8 Flash's list price changes on 1 Jan 2027, and from then Gemini 3.8 Flash is cheaper ($3.00 vs $10.00 blended).
Is Claude Opus 5 better than Gemini 3.8 Flash for coding?
Claude Opus 5 scores higher in coding (70 vs 64 on the category index, where 50 is average). On Arena WebDev, the top shared coding benchmark, it is 1690 for Claude Opus 5 against 1585 for Gemini 3.8 Flash.
Is Claude Opus 5 better than Gemini 3.8 Flash for agents and tool use?
Claude Opus 5 scores higher in agentic tasks (64 vs 51 on the category index, where 50 is average). On Terminal-Bench, the top shared agents & tools benchmark, it is 51.8% for Claude Opus 5 against 19.1% for Gemini 3.8 Flash.
Which is better for long documents?
Gemini 3.8 Flash scores higher on long-context benchmarks (66 vs 65). Both take about 1M tokens: Claude Opus 5 1,000,000, Gemini 3.8 Flash 1,048,576.
Which has lower latency?
Claude Opus 5 (max) answers first: 20.2 s against 25.1 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 5 or Gemini 3.8 Flash?
Gemini 3.8 Flash streams faster: 141 against 57 output tokens per second.
Do independent benchmarks agree on Claude Opus 5 vs Gemini 3.8 Flash?
Across the 53 benchmarks both have, Claude Opus 5 leads 34, Gemini 3.8 Flash leads 18 and 1 is a tie. Independent sources split: Claude Opus 5 leads on AA Intelligence Index v4.3.2; Gemini 3.8 Flash leads on Arena Text.
When was Gemini 3.8 Flash released?
Gemini 3.8 Flash was released on 2 Sept 2026.