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Head-to-head comparison

Claude Opus 4.8 vs. Gemini 3.1 Pro Preview

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

shared result series
2
distinct benchmarks
2
latest retrieval
2026-09-02

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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 3.1 Pro Preview
AttributeClaude Opus 4.8Gemini 3.1 Pro Preview
ProviderAnthropicGoogle
ReleasedMay 2026Feb 19, 2026
AvailabilityLegacyPreview
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 3.1 Pro Preview
Price typeClaude Opus 4.8Gemini 3.1 Pro Preview
API input$5$2 ≤200K / $4 >200K
API output$25$12 ≤200K / $18 >200K
Cache read$0.5$0.2 ≤200K / $0.4 >200K
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 3.1 Pro Preview
API inputUSD per 1M tokens, base tier
Claude Opus 4.8$5
Gemini 3.1 Pro PreviewLower price$2
API outputUSD per 1M tokens, base tier
Claude Opus 4.8$25
Gemini 3.1 Pro PreviewLower price$12
Cache readUSD per 1M tokens, base tier
Claude Opus 4.8$0.5
Gemini 3.1 Pro PreviewLower price$0.2

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 3.1 Pro Preview
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 3.1 Pro PreviewGoogleDirect from developerUp to 200,000 context tokens$2$12Source07/30/2026
GoogleDirect from developerAbove 200,000 context tokens$4$18Source07/30/2026
GoogleVia OpenRoutergoogle-vertex/global$2$12Source09/12/2026
GoogleVia OpenRoutergoogle-vertex/global/flexLowest listed price: $1Lowest listed price: $6Source09/12/2026
GoogleVia OpenRoutergoogle-vertex/global/priority$3.6$21.6Source09/12/2026
Google AI StudioVia OpenRoutergoogle-ai-studio$2$12Source09/12/2026
Google AI StudioVia OpenRoutergoogle-ai-studio/flexLowest listed price: $1Lowest listed price: $6Source09/12/2026
Google AI StudioVia OpenRoutergoogle-ai-studio/priority$3.6$21.6Source09/12/2026

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 1 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 3.1 Pro Preview
BrowseCompOverall. Higher is better. No documented setup difference
Claude Opus 4.884.3 %
Gemini 3.1 Pro PreviewWinner85.9 %
EnigmaEvalOverall. Higher is better. Test setup not documented as identical
Claude Opus 4.823.51% ± 2.41
Gemini 3.1 Pro PreviewHigher measured value36.78% ± 2.71

Key to the marks:better valuebetter, but not conclusivetie

Benchmark scores for Claude Opus 4.8 and Gemini 3.1 Pro Preview
Benchmark and taskClaude Opus 4.8Gemini 3.1 Pro PreviewSource
BrowseCompOverall
Test details
No documented difference in the test setupVersion: 1,266 tasksMetric: accuracyScoring: Higher is betterCross-vendor comparison table with browsing tools. Exact agent systems differ.
84.3 %
Editorial selection from the vendor table, not a complete extract of the comparison cohort.
Winner85.9 %
Editorial selection from the vendor table, not a complete extract of the comparison cohort.
OpenAI
Source details
Data as of: 07/09/2026
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 3.1 Pro Preview: Snapshot: gemini-3.1-pro-preview-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 value36.78% ± 2.71
95% confidence interval: ±2.71
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 3.1 Pro Preview

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-3.1-pro-preview
Pinned endpoint
Google AI Studio | google/gemini-3.1-pro-preview-20260219
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 3.1 Pro Preview with other leading models using the same data and benchmark logic.

View the complete LLM comparison