Head-to-head comparison

Claude Opus 4.6 vs. Gemini 3.5 Flash

Compare published benchmark results from matching versions and cohorts, API pricing, and technical specifications. Any documented test setup differences remain visible.

shared result series: 16
distinct benchmark metrics: 5
latest retrieval: 2026-10-16

First modelSecond model

Specifications

General specifications

Release date, availability, context window, architecture, and published parameter counts at a glance. Undisclosed details remain marked as unavailable.

Specifications for Claude Opus 4.6 and Gemini 3.5 Flash
Attribute	Claude Opus 4.6	Gemini 3.5 Flash
Provider	Anthropic	Google
Released	Feb 2026	May 19, 2026
Availability	Active	Active
Model type	Proprietary	Proprietary
Parameters	Not published	Not published
Architecture	Not published	Not published
Context window	1,000,000 tokens	1,048,576 tokens
Knowledge cutoff	May 2025	Not published
Technical sources	Model, Context	Model

Pricing

API pricing compared

The table compares official standard API rates per 1M tokens, including published cache pricing. Batch, fast, priority, regional surcharges, tool calls, and cloud platform pricing are excluded.

API pricing for Claude Opus 4.6 and Gemini 3.5 Flash
Price type	Claude Opus 4.6	Gemini 3.5 Flash
API input	$5	$1.5
API output	$25	$9
Cache read	$0.5	$0.15
Cache write (5 min.)	$6.25	Not listed
Cache write (1 hr.)	$10	Not listed
Price verified	09/22/2026 Source	09/22/2026 Source

Claude Opus 4.6Gemini 3.5 Flash

API inputUSD per 1M tokens, base tier

Claude Opus 4.6$5

Gemini 3.5 Flash$1.5

API outputUSD per 1M tokens, base tier

Claude Opus 4.6$25

Gemini 3.5 Flash$9

Cache readUSD per 1M tokens, base tier

Claude Opus 4.6$0.5

Gemini 3.5 Flash$0.15

Key to the marks:better valuebetter, but not conclusivetie

Pricing by provider

Direct developer pricing and provider endpoint tariffs routed through OpenRouter are listed separately. Prices are in USD per 1M tokens. Context-dependent direct tiers plus regional, Flex, Priority, and other OpenRouter tariffs remain individually identifiable.

Provider pricing for Claude Opus 4.6 and Gemini 3.5 Flash
Model	Provider	Purchase route and tariff	Input per 1M tokens	Output per 1M tokens	Source
Claude Opus 4.6	Anthropic	Direct from developerStandard API	Lowest listed price: $5	Lowest listed price: $25	Source09/22/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock	Lowest listed price: $5	Lowest listed price: $25	Source10/26/2026
	Anthropic	Via OpenRouteranthropic	Lowest listed price: $5	Lowest listed price: $25	Source10/26/2026
	Azure	Via OpenRouterazure/global	Lowest listed price: $5	Lowest listed price: $25	Source10/26/2026
	Claude Platform on AWS	Via OpenRouterclaude-on-aws	Lowest listed price: $5	Lowest listed price: $25	Source10/26/2026
	Google	Via OpenRoutergoogle-vertex/europe	$5.5	$27.5	Source10/26/2026
	Google	Via OpenRoutergoogle-vertex/global	Lowest listed price: $5	Lowest listed price: $25	Source10/26/2026
Gemini 3.5 Flash	Google	Direct from developerStandard API	$1.5	$9	Source09/22/2026
	Google	Via OpenRoutergoogle-vertex/global	$1.5	$9	Source10/26/2026
	Google	Via OpenRoutergoogle-vertex/global/flex	Lowest listed price: $0.75	Lowest listed price: $4.5	Source10/26/2026
	Google	Via OpenRoutergoogle-vertex/global/priority	$2.7	$16.2	Source10/26/2026
	Google	Via OpenRoutergoogle-vertex/us	$1.65	$9.9	Source10/26/2026
	Google AI Studio	Via OpenRoutergoogle-ai-studio	$1.5	$9	Source10/26/2026
	Google AI Studio	Via OpenRoutergoogle-ai-studio/flex	Lowest listed price: $0.75	Lowest listed price: $4.5	Source10/26/2026
	Google AI Studio	Via OpenRoutergoogle-ai-studio/priority	$2.7	$16.2	Source10/26/2026

Benchmark index

Benchmark index compared

The index combines independent benchmarks on a scale from 0 to 100. A lead only counts when a model comes first in at least 95% of 200 recalculations with randomly redrawn test families. Otherwise both count as level.

Open the AI leaderboard

Claude Opus 4.6

Overall index

No overall score yet

Gemini 3.5 Flash

Overall index

43.4

Claude Opus 4.6 leads in 2 of 5 shared areas. 3 areas are tied.

Area	Claude Opus 4.6	Gemini 3.5 Flash
Codingtied	43.8	31.6
Agentstied	48.0	33.7
Finance	72.9	48.3
Legal	71.5	28.5
Healthtied	63.0	41.2

Performance

Shared benchmarks

Only published results with the same benchmark version, task, metric, and comparison cohort are paired. Different reasoning levels, agents, harnesses, or output limits appear directly in the table.

Capability profile from matched benchmarks

Each axis averages directly matched benchmark families. A value of 100 means the stronger value within this pair, not a universal quality score.

Not enough directly matched categories for a reliable radar

Only 2 of at least 5 categories have comparable, direct model measurements. The benchmark tables below show the available evidence without filling missing axes.

Claude Opus 4.6Gemini 3.5 Flash

LMArena Code Arena WebDevOverall. Higher is better. No documented setup difference

Claude Opus 4.61,546.362

Gemini 3.5 Flash1,499.426

LMArena Vision, Style ControlOverall. Higher is better. No documented setup difference

Claude Opus 4.61,299.232

Gemini 3.5 Flash1,283.659

MedCodeOverall. Higher is better. Test setup not documented as identical

Claude Opus 4.648.244 %

Gemini 3.5 Flash55.825 %

MedScribeOverall. Higher is better. Test setup not documented as identical

Claude Opus 4.686.738 %

Gemini 3.5 Flash76.574 %

Vibe Code Bench v1.1Overall. Higher is better. Test setup not documented as identical

Claude Opus 4.657.573 %

Gemini 3.5 Flash48.683 %

LMArena Code Arena WebDevImage to webdev. Higher is better. No documented setup difference

Claude Opus 4.61,542.687

Gemini 3.5 Flash1,500.53

LMArena Vision, Style ControlChinese. Higher is better. No documented setup difference

Claude Opus 4.61,351.953

Gemini 3.5 Flash1,348.415

LMArena Code Arena WebDevWebdev. Higher is better. No documented setup difference

Claude Opus 4.61,546.362

Gemini 3.5 Flash1,499.426

LMArena Vision, Style ControlCreative writing vision. Higher is better. No documented setup difference

Claude Opus 4.61,309.447

Gemini 3.5 Flash1,271.63

LMArena Code Arena WebDevWebdev-html. Higher is better. No documented setup difference

Claude Opus 4.61,558.715

Gemini 3.5 Flash1,513.471

LMArena Vision, Style ControlDiagram. Higher is better. No documented setup difference

Claude Opus 4.61,324.675

Gemini 3.5 Flash1,308.968

LMArena Code Arena WebDevWebdev-react. Higher is better. No documented setup difference

Claude Opus 4.61,538.872

Gemini 3.5 Flash1,494.909

Key to the marks:better valuebetter, but not conclusivetie

Our model tests

Our tests

SVG short test

One SVG prompt and fixed output settings. Captures are shown only with 0 reported reasoning tokens or documented lack of reasoning controls. Identical test conditions do not make the models' internal compute identical.

Shared test round: 43b8c5c46830

Claude Opus 4.6

Gemini 3.5 Flash

Unavailable in this round

Earlier tests

Pelican on a bicycle

A community classic for free-form SVG drawing.

Claude Opus 4.6

Reasoning (requested): high

Current attempt

Run date: Oct 1, 2026
API provider: openrouter
Requested API model: anthropic/claude-opus-4.6
API model reported in response: anthropic/claude-opus-4.6
Reasoning setting: high
Pinned endpoint: Anthropic | anthropic/claude-4.6-opus-20260205
Temperature: Provider default
Token limit including reasoning: 8,192 tokens
Test protocol: community-visual-tests-v1
Technical checks: Passed, not a quality rating
Response time: 85.1 s

Visually reviewed. This individual test does not establish overall model quality.

Gemini 3.5 Flash

The response reached the token limit. No complete recording is available.

Reasoning (requested): high

Current attempt

Run date: Oct 6, 2026
API provider: openrouter
Requested API model: google/gemini-3.5-flash
API model reported in response: google/gemini-3.5-flash
Reasoning setting: high
Pinned endpoint: Google AI Studio | google/gemini-3.5-flash-20260519
Temperature: Provider default
Token limit including reasoning: 8,192 tokens
Test protocol: community-visual-tests-v1
Technical checks: Failed
Response time: 31.7 s

Not yet visually reviewed. A successful recording does not confirm correct physics or full compliance with the prompt.

Earlier attempts (3)

Oct 2, 2026API request failedReasoning setting: high
Oct 1, 2026API request failedReasoning setting: high
Sep 7, 2026API request failedReasoning setting: high

Prompt and test conditions

Generate an SVG of a pelican riding a bicycle

Token limit including reasoning: 8,192 tokens

Task origin (Simon Willison)

How to read this comparison

Winning one benchmark is not an overall verdict

Your workload, budget, and required context length matter most. A coding benchmark says little about visual understanding or agent performance.

The standard price table uses direct developer rates. The provider comparison labels OpenRouter endpoints, regions, and special tariffs separately.

Every result links to its measurement source and retrieval date. Labels distinguish vendor reports, official benchmark leaderboards, and independent evaluations. Disputed or archived results are excluded.

More matchups

Compare Claude Opus 4.6 and Gemini 3.5 Flash with other leading models using the same data and benchmark logic.

View the complete LLM comparison

Benchmark and task	Claude Opus 4.6	Gemini 3.5 Flash	Source
LMArena Code Arena WebDevOverall Test details No documented difference in the test setupVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Code Arena WebDev Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 19,443 published pairwise votes.Gemini 3.5 Flash: Arena rating from 9,415 published pairwise votes.	Winner1,546.362 95% confidence interval: ±5.46The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,499.426 95% confidence interval: ±7.264The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlOverall Test details No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 22,304 published pairwise votes.Gemini 3.5 Flash: Arena rating from 13,103 published pairwise votes.	Winner1,299.232 95% confidence interval: ±6.456The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,283.659 95% confidence interval: ±6.995The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
MedCodeOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterClaude Opus 4.6: Compute: max, Temperature: 1, Output limit: 30,000 tokens Gemini 3.5 Flash: Reasoning: high, Temperature: 1, Output limit: 30,000 tokens	48.244 %	Higher measured value55.825 %	Vals AI Source details Data as of: 10/13/2026
MedScribeOverall Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterClaude Opus 4.6: Compute: max, Temperature: 1, Output limit: 30,000 tokens Gemini 3.5 Flash: Reasoning: high, Temperature: 1, Output limit: 30,000 tokens	Higher measured value86.738 %	76.574 %	Vals AI Source details Data as of: 10/13/2026
Vibe Code Bench v1.1Overall Test details Test setup not documented as identicalNo direct winnerVersion: 1.1Metric: accuracyScoring: Higher is betterClaude Opus 4.6: Compute: max, Harness: OpenHands, Temperature: 1, Output limit: 128,000 tokens Gemini 3.5 Flash: Reasoning: high, Harness: OpenHands, Temperature: 1, Output limit: 65,536 tokens	Higher measured value57.573 %	48.683 %	Vals AI Source details Data as of: 10/12/2026
LMArena Code Arena WebDevImage to webdev Test details No documented difference in the test setupVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Code Arena WebDev Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 7,930 published pairwise votes.Gemini 3.5 Flash: Arena rating from 2,020 published pairwise votes.	Winner1,542.687 95% confidence interval: ±8.913The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,500.53 95% confidence interval: ±13.81The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Vision, Style ControlChinese Test details No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 1,488 published pairwise votes.Gemini 3.5 Flash: Arena rating from 820 published pairwise votes.	No clear lead1,351.953 95% confidence interval: ±17.967The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,348.415 95% confidence interval: ±22.781The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Code Arena WebDevWebdev Test details No documented difference in the test setupVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Code Arena WebDev Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 19,443 published pairwise votes.Gemini 3.5 Flash: Arena rating from 9,415 published pairwise votes.	Winner1,546.362 95% confidence interval: ±5.46The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,499.426 95% confidence interval: ±7.264The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlCreative writing vision Test details No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 1,405 published pairwise votes.Gemini 3.5 Flash: Arena rating from 1,103 published pairwise votes.	Winner1,309.447 95% confidence interval: ±16.801The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,271.63 95% confidence interval: ±19.167The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Code Arena WebDevWebdev-html Test details No documented difference in the test setupVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Code Arena WebDev Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 2,474 published pairwise votes.Gemini 3.5 Flash: Arena rating from 1,143 published pairwise votes.	Winner1,558.715 95% confidence interval: ±13.217The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,513.471 95% confidence interval: ±19.06The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlDiagram Test details No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 5,999 published pairwise votes.Gemini 3.5 Flash: Arena rating from 3,391 published pairwise votes.	No clear lead1,324.675 95% confidence interval: ±9.238The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,308.968 95% confidence interval: ±10.974The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Code Arena WebDevWebdev-react Test details No documented difference in the test setupVersion: webdevMetric: WebDev Arena Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Code Arena WebDev Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Code Arena WebDevClaude Opus 4.6: Arena rating from 15,177 published pairwise votes.Gemini 3.5 Flash: Arena rating from 6,804 published pairwise votes.	Winner1,538.872 95% confidence interval: ±6.058The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,494.909 95% confidence interval: ±8.379The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/13/2026
LMArena Vision, Style ControlEnglish Test details No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 9,251 published pairwise votes.Gemini 3.5 Flash: Arena rating from 4,776 published pairwise votes.	Winner1,301.128 95% confidence interval: ±8.811The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,278.187 95% confidence interval: ±10.222The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Vision, Style ControlHomework Test details No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 2,849 published pairwise votes.Gemini 3.5 Flash: Arena rating from 1,505 published pairwise votes.	No clear lead1,324.17 95% confidence interval: ±12.006The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,306.005 95% confidence interval: ±15.615The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Vision, Style ControlHumor Test details No documented difference in the test setupNo clear leadVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 869 published pairwise votes.Gemini 3.5 Flash: Arena rating from 553 published pairwise votes.	No clear lead1,296.35 95% confidence interval: ±21.068The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,288.271 95% confidence interval: ±26.134The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
LMArena Vision, Style ControlOcr Test details No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterClaude Opus 4.6: Snapshot: claude-opus-4-6-high, Reasoning: high, Harness: Arena Vision, style control Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Harness: Arena Vision, style controlClaude Opus 4.6: Arena rating from 15,929 published pairwise votes.Gemini 3.5 Flash: Arena rating from 9,077 published pairwise votes.	Winner1,313.477 95% confidence interval: ±6.575The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	1,293.436 95% confidence interval: ±7.265The Arena score measures human preference rather than a fixed capability test. The confidence interval, Arena category, and model configuration are part of the result.	LMArena Source details Data as of: 10/09/2026
Key to the marks:better valuebetter, but not conclusivetie

Claude Opus 4.6 vs. Gemini 3.5 Flash

Change model selection

General specifications

API pricing compared

Benchmark index compared

Shared benchmarks

Capability profile from matched benchmarks

Our tests

SVG short test

Claude Opus 4.6

Gemini 3.5 Flash

Pelican on a bicycle

Winning one benchmark is not an overall verdict

Related LLM comparisons