API cost decision in 10 seconds

Claude Opus Latest vs Gemini 3.1 Pro Preview Custom Tools

Pick Gemini 3.1 Pro Preview Custom Tools when budget and context both matter.

Pricing data updated: 2026-05-26T11:08:00Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Gemini 3.1 Pro Preview Custom Tools when budget and context both matter.

On the standard 1M input plus 500K output workload, Gemini 3.1 Pro Preview Custom Tools is estimated at $8 vs $17.5 for Claude Opus Latest, saving $9.5 (54.3% lower).

Cost-first pickGemini 3.1 Pro Preview Custom Tools

Context-first pickGemini 3.1 Pro Preview Custom Tools

Sample savings$9.554.3%

10x traffic gap$95

Gemini 3.1 Pro Preview Custom Tools is cheaper on the standard workload and also has the larger context window. At 10x that traffic, the same price gap is about $95. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

Gemini 3.1 Pro Preview Custom Tools stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	Claude Opus Latest	Gemini 3.1 Pro Preview Custom Tools
Input-heavy / RAG	5M input + 500K output	Gemini 3.1 Pro Preview Custom Tools	$37.5	$16
Balanced workload	1M input + 1M output	Gemini 3.1 Pro Preview Custom Tools	$30	$14
Output-heavy chatbot	1M input + 5M output	Gemini 3.1 Pro Preview Custom Tools	$130	$62

Cheaper input Gemini 3.1 Pro Preview Custom Tools $5 vs $2 / 1M

Gemini 3.1 Pro Preview Custom Tools is $3 cheaper per 1M input tokens (60% lower; 2.5x difference).

Cheaper output Gemini 3.1 Pro Preview Custom Tools $25 vs $12 / 1M

Gemini 3.1 Pro Preview Custom Tools is $13 cheaper per 1M output tokens (52% lower; 2.08x difference).

Larger context Gemini 3.1 Pro Preview Custom Tools 1M vs 1.05M

Gemini 3.1 Pro Preview Custom Tools has 48.76K more context (1.05x larger).

Sample workload Gemini 3.1 Pro Preview Custom Tools $17.5 vs $8

Gemini 3.1 Pro Preview Custom Tools is $9.5 cheaper on the standard workload (54.3% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Claude Opus Latest Calculating… Estimated API cost

Gemini 3.1 Pro Preview Custom Tools Calculating… Estimated API cost

Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

Gemini 3.1 Pro Preview Custom Tools has the lower input price; Gemini 3.1 Pro Preview Custom Tools has the lower output price; Gemini 3.1 Pro Preview Custom Tools offers the larger context window. For the 1M input plus 500K output sample, Gemini 3.1 Pro Preview Custom Tools is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $17.5 for Claude Opus Latest and $8 for Gemini 3.1 Pro Preview Custom Tools.

Best Fit

Choose Claude Opus Latest when its provider, model quality, latency, or availability is more important than the numeric price/context winner.

Choose Gemini 3.1 Pro Preview Custom Tools when you care most about lower input-token price, lower output-token price, and larger context window.

Decision Notes

On the standard 1M input plus 500K output workload, Gemini 3.1 Pro Preview Custom Tools is estimated at $8 vs $17.5 for Claude Opus Latest, saving $9.5 (54.3% lower).
Gemini 3.1 Pro Preview Custom Tools is $9.5 cheaper on the standard workload (54.3% lower).
Gemini 3.1 Pro Preview Custom Tools is $3 cheaper per 1M input tokens (60% lower; 2.5x difference).
Gemini 3.1 Pro Preview Custom Tools is $13 cheaper per 1M output tokens (52% lower; 2.08x difference).
Gemini 3.1 Pro Preview Custom Tools has 48.76K more context (1.05x larger).

Head-to-Head Specs

Feature	Claude Opus Latest (Anthropic)	Gemini 3.1 Pro Preview Custom Tools (Google)
Input Price prompt tokens per 1M	$5	$2
Completion Price per 1M tokens	$25	$12
Sample Workload Cost 1M input + 500K output	$17.5	$8
Context Window	1M	1.05M
Release Date	2026-04-21	2026-02-25

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Gemini 3.1 Pro Preview Custom Tools	On the standard 1M input plus 500K output workload, Gemini 3.1 Pro Preview Custom Tools is estimated at $8 vs $17.5 for Claude Opus Latest, saving $9.5 (54.3% lower).
High-volume input processing	Gemini 3.1 Pro Preview Custom Tools	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Gemini 3.1 Pro Preview Custom Tools	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Gemini 3.1 Pro Preview Custom Tools	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

Claude 3 Haiku can replace Claude Opus Latest when lower sample workload cost matters most: $0.88.
Claude 3.5 Haiku can replace Claude Opus Latest when lower sample workload cost matters most: $2.8.
Anthropic Claude Haiku Latest can replace Claude Opus Latest when lower sample workload cost matters most: $3.5.
Claude Haiku 4.5 can replace Claude Opus Latest when lower sample workload cost matters most: $3.5.

Larger context near this budget

Llama 4 Scout offers 10M context with $0.23 sample workload cost.
Grok 4.20 Multi-Agent offers 2M context with $5 sample workload cost.
Grok 4.20 offers 2M context with $2.5 sample workload cost.
OpenAI GPT Latest offers 1.05M context with $20 sample workload cost.

Popular competitors

No popular competitor is currently available.

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

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Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

Open largest context models

Provider catalogs

Compare models within provider hubs before choosing a final API vendor.

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Anthropic catalog

Review all tracked Anthropic models before deciding whether this matchup is the right shortlist.

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Google catalog

Check other Google models with comparable pricing, context, or release timing.

Open Google models

Claude Opus Latest

This model always redirects to the latest model in the Claude Opus family.

Gemini 3.1 Pro Preview Custom Tools

Gemini 3.1 Pro Preview Custom Tools is a variant of Gemini 3.1 Pro that improves tool selection behavior by preventing overuse of a general bash tool when more efficient third-party...