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comparison

Claude Opus 4.8 vs Gemini 3.1 Pro

Token pricing, context window and real monthly cost, side by side. Gemini 3.1 Pro is the cheaper of the two for a typical workload — about 2.2× less.

cheaper for a typical workload
Gemini 3.1 Pro
saves 55% vs Claude Opus 4.8 at 1,500 in / 500 out × 200,000/mo
Claude Opus 4.8 $4,000/mo
Gemini 3.1 Pro $1,800/mo
Flagship vs Flagship comparable technical class at a lower rate — the better value

Positioned by published specs — size, context and modality — not measured performance; a smaller model can sometimes outperform a larger one on your task.

Cost versus technical classClaude Opus 4.8: $4,000/mo, Flagship class. Gemini 3.1 Pro: $1,800/mo, Flagship class. Plotted by monthly cost (horizontal) against technical class from size and context (vertical).best valuepremiumbudgetoverpricedClaude Opus 4.8$4,000/mo · FlagshipGemini 3.1 Pro$1,800/mo · Flagship← lower cost · monthly $ · higher cost →
↑ technical class (size & context)
Same technical class

Gemini 3.1 Pro and Claude Opus 4.8 are the same class (Flagship) on size & context, so they're plausible substitutes — decide on price, modality and provider fit.

Claude Opus 4.8 versus Gemini 3.1 Pro specifications and price.
metric Claude Opus 4.8 Gemini 3.1 Pro
Input / 1M $5.00 $2.00
Output / 1M $25.00 $12.00
Context 1M 1.0M
Technical class Flagship Flagship
Cost @ typical workload $4,000/mo $1,800/mo
Modality text + image text + image + audio + video
Price source list list
Provider Anthropic Google

Snapshot . Cost uses a typical workload; tune it in the calculator. How we measure →

Which should you pick?

On a typical workload, Gemini 3.1 Pro costs $1,800/mo against Claude Opus 4.8's $4,000/mo — roughly 2.2× cheaper. But the ranking depends on your output-to-input ratio: output is the pricier direction for both, so an output-heavy job (code generation, long answers) widens the gap while an input-heavy one (summarization, retrieval) narrows it. If you need to fit more in a single prompt, Gemini 3.1 Pro has the larger 1.0M-token window (~1,573 pages). By technical class — a spec read of size and context, not measured capability — both are Flagship, so this is a like-for-like price decision.

These are list and routed market prices, not measured outcomes. Two models at the same rate can still cost different amounts to finish the same task, because verbose or reasoning-heavy models emit more tokens. That gap is exactly what measured cost-per-task captures. The technical-class read above is likewise spec-based — size, context and modality, not measured performance — so a smaller model can still outperform a larger one on your specific task.

Frequently asked questions

Is Claude Opus 4.8 or Gemini 3.1 Pro cheaper?

For a typical workload (1,500 input + 500 output tokens × 200,000 requests/month), Gemini 3.1 Pro costs $1,800/mo versus $4,000/mo for Claude Opus 4.8 — about 2.2× less. Because output is priced higher than input, the winner can flip if your workload writes much more or less than this; check your own numbers in the calculator.

What's the main difference between Claude Opus 4.8 and Gemini 3.1 Pro?

On price, Claude Opus 4.8 is $5.00/$25.00 per 1M (in/out) and Gemini 3.1 Pro is $2.00/$12.00. By technical class (size & context) they're the same — both Flagship. Gemini 3.1 Pro has the larger context window at 1.0M tokens.

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