Technology

Gemini 3.1 Pro vs Claude Opus 4.8: Cost-Efficient Generalist or Peak Coding Model?

Gemini 3.1 Pro vs Claude Opus 4.8 compared on coding, reasoning, price and context. Opus wins peak accuracy (88.6% SWE-bench); Gemini is 2.5x cheaper on input. Which to pick in 2026.

3
Gemini 3.1 Pro
vs
3
Claude Opus 4.8
Quick Verdict

Pick by workload, not by headline. Claude Opus 4.8 is the model to beat for hard, agentic coding: 88.6% on SWE-bench Verified versus Gemini 3.1 Pro's 80.6%, plus dynamic workflows that fan out hundreds of parallel subagents and a 2.5x fast mode at the same base price. If correctness on complex code changes is what you are paying for, Opus earns its premium. Gemini 3.1 Pro wins the economics and the generalist reasoning: input tokens cost $2 per million against Opus's $5, output $12 against $25, and it leads on abstract reasoning (77.1% ARC-AGI-2) and science QA (94.3% GPQA Diamond) with a native multimodal stack. For high-volume, cost-sensitive pipelines, long-context document work, or multimodal tasks, Gemini is the rational default. Many teams run both: Opus for the hardest coding and agent runs, Gemini 3.1 Pro for everything where price-per-token and multimodal breadth matter more than the last few points of coding accuracy. If a 2M-token window is your blocker, wait for Gemini 3.5 Pro rather than forcing today's models.

Detailed Comparison

A side-by-side analysis of key factors to help you make the right choice.

Factor
Gemini 3.1 ProRecommended
Claude Opus 4.8Winner
Coding accuracy (SWE-bench Verified)
80.6% — strong, but a step behind the coding leader
88.6% — best-in-class on this benchmark
Price per 1M tokens (input / output)
$2 / $12 — roughly half the cost
$5 / $25 — premium pricing
Context window
1M tokens
1M tokens
Abstract reasoning & science QA
77.1% ARC-AGI-2, 94.3% GPQA Diamond — headline strengths
Very capable but coding-tilted; these are not its lead benchmarks
Agentic workflows
Solid tool use with a Deep Think reasoning mode
Dynamic workflows that fan out hundreds of parallel subagents
Native multimodality (image / video / audio in)
Native multimodal stack across modalities
Strong text and vision, narrower modality breadth
Code reliability
Reliable, but higher error rate on hard changes than Opus
~4x fewer code bugs than Opus 4.7 at the same price
Total Score3/ 73/ 71 ties
Coding accuracy (SWE-bench Verified)
Gemini 3.1 Pro
80.6% — strong, but a step behind the coding leader
Claude Opus 4.8
88.6% — best-in-class on this benchmark
Price per 1M tokens (input / output)
Gemini 3.1 Pro
$2 / $12 — roughly half the cost
Claude Opus 4.8
$5 / $25 — premium pricing
Context window
Gemini 3.1 Pro
1M tokens
Claude Opus 4.8
1M tokens
Abstract reasoning & science QA
Gemini 3.1 Pro
77.1% ARC-AGI-2, 94.3% GPQA Diamond — headline strengths
Claude Opus 4.8
Very capable but coding-tilted; these are not its lead benchmarks
Agentic workflows
Gemini 3.1 Pro
Solid tool use with a Deep Think reasoning mode
Claude Opus 4.8
Dynamic workflows that fan out hundreds of parallel subagents
Native multimodality (image / video / audio in)
Gemini 3.1 Pro
Native multimodal stack across modalities
Claude Opus 4.8
Strong text and vision, narrower modality breadth
Code reliability
Gemini 3.1 Pro
Reliable, but higher error rate on hard changes than Opus
Claude Opus 4.8
~4x fewer code bugs than Opus 4.7 at the same price

Key Statistics

Real data from verified industry sources to support your decision.

Gemini 3.1 Pro scores 80.6% on SWE-bench Verified

nxcode.io

Claude Opus 4.8 scores 88.6% on SWE-bench Verified

llm-stats.com

Gemini 3.1 Pro is priced at $2 / $12 per 1M input / output tokens

nxcode.io

Claude Opus 4.8 is priced at $5 / $25 per 1M input / output tokens

vm0.ai

Gemini 3.1 Pro hits 77.1% on ARC-AGI-2 (up from 31.1% for Gemini 3 Pro) and 94.3% on GPQA Diamond

nxcode.io

Claude Opus 4.8 scores 74.6% on Terminal-Bench 2.1 and 69.2% on SWE-bench Pro

morphllm.com

All statistics come from verified third-party sources. Source, year, and direct link are shown on each metric.

When to Choose Each Option

Clear guidance based on your specific situation and needs.

Choose Gemini 3.1 Pro when...

  • Token cost and throughput drive your budget more than the last points of coding accuracy
  • You run long-context document analysis or native multimodal tasks (image, video, audio)
  • You need strong abstract reasoning and science-QA performance
  • You are building high-volume, cost-sensitive pipelines

Choose Claude Opus 4.8 when...

  • You need the highest coding accuracy on hard, real-world code changes
  • You run agentic workflows with many parallel subagents
  • Fewer code bugs and higher reliability justify a premium price
  • You want a fast mode that keeps the same base pricing

Our Recommendation

Pick by workload, not by headline. Claude Opus 4.8 is the model to beat for hard, agentic coding: 88.6% on SWE-bench Verified versus Gemini 3.1 Pro's 80.6%, plus dynamic workflows that fan out hundreds of parallel subagents and a 2.5x fast mode at the same base price. If correctness on complex code changes is what you are paying for, Opus earns its premium. Gemini 3.1 Pro wins the economics and the generalist reasoning: input tokens cost $2 per million against Opus's $5, output $12 against $25, and it leads on abstract reasoning (77.1% ARC-AGI-2) and science QA (94.3% GPQA Diamond) with a native multimodal stack. For high-volume, cost-sensitive pipelines, long-context document work, or multimodal tasks, Gemini is the rational default. Many teams run both: Opus for the hardest coding and agent runs, Gemini 3.1 Pro for everything where price-per-token and multimodal breadth matter more than the last few points of coding accuracy. If a 2M-token window is your blocker, wait for Gemini 3.5 Pro rather than forcing today's models.

Frequently Asked Questions

Common questions about this comparison answered.

For hard coding and agentic work, yes: Opus 4.8 leads SWE-bench Verified at 88.6% versus 80.6% and fans out hundreds of parallel subagents. But Gemini 3.1 Pro is roughly half the price per token and leads on abstract reasoning and multimodality, so 'better' depends on whether you optimize for peak coding accuracy or cost-efficient reasoning at scale.
Gemini 3.1 Pro lists at $2 per million input tokens and $12 per million output tokens, versus $5 and $25 for Claude Opus 4.8 — roughly 2.5x cheaper on input and about 2x cheaper on output. For high-volume workloads the gap compounds quickly.
Yes — both ship a 1M-token context window today. Google's upcoming Gemini 3.5 Pro is reported to expand this to 2M tokens, but that model is expected around mid-July 2026 and is not yet generally available.
For the hardest agentic coding, Claude Opus 4.8 is the stronger default thanks to its SWE-bench lead and parallel-subagent workflows. For cost-sensitive or multimodal agent pipelines, Gemini 3.1 Pro is a rational choice, and many teams route the hardest runs to Opus while keeping Gemini for volume.

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