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Head-to-head comparison

Claude Opus 4.8 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
1
distinct benchmarks
1
latest retrieval
2026-08-26

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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 4.8 and Gemini 3.5 Flash
AttributeClaude Opus 4.8Gemini 3.5 Flash
ProviderAnthropicGoogle
ReleasedMay 2026May 19, 2026
AvailabilityLegacyActive
Model typeProprietaryProprietary
ParametersNot publishedNot published
ArchitectureNot publishedNot published
Context window1,000,000 tokens1,048,576 tokens
Knowledge cutoffJanuary 2026Not published
Technical sourcesModel, Knowledge cutoffModel

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 4.8 and Gemini 3.5 Flash
Price typeClaude Opus 4.8Gemini 3.5 Flash
API input$5$1.5
API output$25$9
Cache read$0.5$0.15
Cache write (5 min.)$6.25Not listed
Cache write (1 hr.)$10Not listed
Price verified07/30/2026 Source07/30/2026 Source
Claude Opus 4.8Gemini 3.5 Flash
API inputUSD per 1M tokens, base tier
Claude Opus 4.8$5
Gemini 3.5 FlashLower price$1.5
API outputUSD per 1M tokens, base tier
Claude Opus 4.8$25
Gemini 3.5 FlashLower price$9
Cache readUSD per 1M tokens, base tier
Claude Opus 4.8$0.5
Gemini 3.5 FlashLower price$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.

No provider tariff for Claude Opus 4.8 is available in the stored OpenRouter snapshot. The official direct price is still shown.

Provider pricing for Claude Opus 4.8 and Gemini 3.5 Flash
ModelProviderPurchase route and tariffInput per 1M tokensOutput per 1M tokensSource
Claude Opus 4.8AnthropicDirect from developerStandard APILowest listed price: $5Lowest listed price: $25Source07/30/2026
Gemini 3.5 FlashGoogleDirect from developerStandard API$1.5$9Source07/30/2026
GoogleVia OpenRoutergoogle-vertex/global$1.5$9Source09/12/2026
GoogleVia OpenRoutergoogle-vertex/global/flexLowest listed price: $0.75Lowest listed price: $4.5Source09/12/2026
GoogleVia OpenRoutergoogle-vertex/global/priority$2.7$16.2Source09/12/2026
GoogleVia OpenRoutergoogle-vertex/us$1.65$9.9Source09/12/2026
Google AI StudioVia OpenRoutergoogle-ai-studio$1.5$9Source09/12/2026
Google AI StudioVia OpenRoutergoogle-ai-studio/flexLowest listed price: $0.75Lowest listed price: $4.5Source09/12/2026
Google AI StudioVia OpenRoutergoogle-ai-studio/priority$2.7$16.2Source09/12/2026

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

Claude Opus 4.8Gemini 3.5 Flash
EnigmaEvalOverall. Higher is better. Test setup not documented as identical
Claude Opus 4.823.51% ± 2.41
Gemini 3.5 FlashHigher measured value25.41% ± 2.45

Key to the marks:better valuebetter, but not conclusivetie

Benchmark scores for Claude Opus 4.8 and Gemini 3.5 Flash
Benchmark and taskClaude Opus 4.8Gemini 3.5 FlashSource
EnigmaEvalOverall
Test details
Test setup not documented as identicalNo direct winnerVersion: open-source release 2026-07-23Metric: pass@1 accuracyScoring: Higher is betterClaude Opus 4.8: Snapshot: claude-opus-4.8-xhigh, Reasoning: xhigh, Attempts: pass@1
Gemini 3.5 Flash: Snapshot: gemini-3.5-flash-high, Reasoning: high, Attempts: pass@1
Complex multimodal puzzles with exact answer matching and one attempt.
23.51% ± 2.41
95% confidence interval: ±2.41
Higher measured value25.41% ± 2.45
95% confidence interval: ±2.45
Scale AI
Source details
Data as of: 07/23/2026

Key to the marks:better valuebetter, but not conclusivetie

Our model tests

Community tests you can inspect

Compare how the models respond to the same prompt. Each test shows the first attempt, with no subsequent fixes to the generated code. These results do not contribute to an overall score.

Pelican on a bicycle

A community classic for free-form SVG drawing.

Claude Opus 4.8

Not tested yet

Gemini 3.5 Flash

API access was unavailable for this run. The model was not evaluated.

First attempt
Run date
7 Sept 2026
API provider
openrouter
Requested API model
google/gemini-3.5-flash
Pinned endpoint
Google AI Studio | google/gemini-3.5-flash-20260519
Reasoning setting
high
Temperature
Provider default
Token limit including reasoning
8,192 tokens
Test protocol
community-visual-tests-v1
Technical checks
Not run

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

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 4.8 and Gemini 3.5 Flash with other leading models using the same data and benchmark logic.

View the complete LLM comparison