API cost decision in 10 seconds

GPT-5.4 Mini vs Gemini 3.1 Pro Preview Custom Tools

Pick GPT-5.4 Mini for lower cost; pick Gemini 3.1 Pro Preview Custom Tools only if the larger context window matters more.

Page updated:  Data confirmed:  Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick GPT-5.4 Mini for lower cost; pick Gemini 3.1 Pro Preview Custom Tools only if the larger context window matters more.

On the standard 1M input plus 500K output workload, GPT-5.4 Mini is estimated at $3 vs $8 for Gemini 3.1 Pro Preview Custom Tools, saving $5 (62.5% lower).

Cost-first pickGPT-5.4 Mini
Context-first pickGemini 3.1 Pro Preview Custom Tools
Sample savings$562.5%
10x traffic gap$50

Gemini 3.1 Pro Preview Custom Tools has more context, but GPT-5.4 Mini saves $5 on the standard workload. At 10x that traffic, the same price gap is about $50. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

GPT-5.4 Mini stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickGPT-5.4 MiniGemini 3.1 Pro Preview Custom Tools
Input-heavy / RAG5M input + 500K outputGPT-5.4 Mini$6$16
Balanced workload1M input + 1M outputGPT-5.4 Mini$5.25$14
Output-heavy chatbot1M input + 5M outputGPT-5.4 Mini$23.25$62
Cheaper input GPT-5.4 Mini $0.75 vs $2 / 1M

GPT-5.4 Mini is $1.25 cheaper per 1M input tokens (62.5% lower; 2.67x difference).

Cheaper output GPT-5.4 Mini $4.5 vs $12 / 1M

GPT-5.4 Mini is $7.5 cheaper per 1M output tokens (62.5% lower; 2.67x difference).

Larger context Gemini 3.1 Pro Preview Custom Tools 400K vs 1.05M

Gemini 3.1 Pro Preview Custom Tools has 648.76K more context (2.62x larger).

Sample workload GPT-5.4 Mini $3 vs $8

GPT-5.4 Mini is $5 cheaper on the standard workload (62.5% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
GPT-5.4 Mini 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

GPT-5.4 Mini has the lower input price; GPT-5.4 Mini 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, GPT-5.4 Mini is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $3 for GPT-5.4 Mini and $8 for Gemini 3.1 Pro Preview Custom Tools.

Best Fit

Choose GPT-5.4 Mini when you care most about lower input-token price, and lower output-token price.

Choose Gemini 3.1 Pro Preview Custom Tools when you care most about larger context window.

Decision Notes
  • On the standard 1M input plus 500K output workload, GPT-5.4 Mini is estimated at $3 vs $8 for Gemini 3.1 Pro Preview Custom Tools, saving $5 (62.5% lower).
  • GPT-5.4 Mini is $5 cheaper on the standard workload (62.5% lower).
  • GPT-5.4 Mini is $1.25 cheaper per 1M input tokens (62.5% lower; 2.67x difference).
  • GPT-5.4 Mini is $7.5 cheaper per 1M output tokens (62.5% lower; 2.67x difference).
  • Gemini 3.1 Pro Preview Custom Tools has 648.76K more context (2.62x larger).
Head-to-Head Specs
FeatureGPT-5.4 Mini
(OpenAI)
Gemini 3.1 Pro Preview Custom Tools
(Google)
Input Price
prompt tokens per 1M
$0.75$2
Completion Price
per 1M tokens
$4.5$12
Sample Workload Cost
1M input + 500K output
$3$8
Context Window400K1.05M
Release Date

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productionGPT-5.4 MiniOn the standard 1M input plus 500K output workload, GPT-5.4 Mini is estimated at $3 vs $8 for Gemini 3.1 Pro Preview Custom Tools, saving $5 (62.5% lower).
High-volume input processingGPT-5.4 MiniLower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsGPT-5.4 MiniLower output-token price matters most when assistants generate many completion tokens.
RAG or long-document workGemini 3.1 Pro Preview Custom ToolsA larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps
  • gpt-oss-120b (free) can replace GPT-5.4 Mini when lower sample workload cost matters most: $0.
  • gpt-oss-20b (free) can replace GPT-5.4 Mini when lower sample workload cost matters most: $0.
  • gpt-oss-20b can replace GPT-5.4 Mini when lower sample workload cost matters most: $0.1.
  • gpt-oss-120b can replace GPT-5.4 Mini when lower sample workload cost matters most: $0.13.
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.
  • GPT-5.4 offers 1.05M context with $10 sample workload cost.

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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OpenAI catalog

Review all tracked OpenAI 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
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