LLM Reference

Gemini 3.1 Pro Preview Custom Tools vs GPT-4o-mini Search Preview

Gemini 3.1 Pro Preview Custom Tools (2026) and GPT-4o-mini Search Preview (2025) are compact production models from Google DeepMind and OpenAI. Gemini 3.1 Pro Preview Custom Tools ships a 1m-token context window, while GPT-4o-mini Search Preview ships a 128k-token context window. On pricing, GPT-4o-mini Search Preview costs $0.15/1M input tokens versus $2/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.

GPT-4o-mini Search Preview is ~1233% cheaper at $0.15/1M; pay for Gemini 3.1 Pro Preview Custom Tools only for long-context analysis.

Decision scorecard

Local evidence first
SignalGemini 3.1 Pro Preview Custom ToolsGPT-4o-mini Search Preview
Best formultimodal apps and long-context analysisprovider-routed production
Decision fitRAG, Long context, and VisionRAG, Long context, and Classification
Context window1m128k
Cheapest output$12/1M tokens$0.60/1M tokens
Provider routes1 tracked2 tracked
Shared benchmarks0 shared0 shared

Decision tradeoffs

Choose Gemini 3.1 Pro Preview Custom Tools when...
  • Gemini 3.1 Pro Preview Custom Tools has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Gemini 3.1 Pro Preview Custom Tools uniquely exposes Vision and Multimodal in local model data.
  • Local decision data tags Gemini 3.1 Pro Preview Custom Tools for RAG, Long context, and Vision.
Choose GPT-4o-mini Search Preview when...
  • GPT-4o-mini Search Preview has the lower cheapest tracked output price at $0.60/1M tokens.
  • GPT-4o-mini Search Preview has broader tracked provider coverage for fallback and route flexibility.
  • Local decision data tags GPT-4o-mini Search Preview for RAG, Long context, and Classification.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output route or tier on this page.

Lower estimate GPT-4o-mini Search Preview

Gemini 3.1 Pro Preview Custom Tools

$4,600

Cheapest tracked route/tier: OpenRouter

GPT-4o-mini Search Preview

$270

Cheapest tracked route/tier: OpenRouter

Estimated monthly gap: $4,330. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Gemini 3.1 Pro Preview Custom Tools -> GPT-4o-mini Search Preview
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • GPT-4o-mini Search Preview is $11.40/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Vision and Multimodal before moving production traffic.
GPT-4o-mini Search Preview -> Gemini 3.1 Pro Preview Custom Tools
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • Gemini 3.1 Pro Preview Custom Tools is $11.40/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Gemini 3.1 Pro Preview Custom Tools adds Vision and Multimodal in local capability data.

Specs

Specification
Released2026-01-012025-02-26
Context window1m128k
Parameters
ArchitectureDecoder OnlyDecoder Only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
WeightsNot releasedNot released
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff2025-012023-10

Pricing and availability

Pricing attributeGemini 3.1 Pro Preview Custom ToolsGPT-4o-mini Search Preview
Input price$2/1M tokens$0.15/1M tokens
Output price$12/1M tokens$0.60/1M tokens
Providers

Capabilities

CapabilityGemini 3.1 Pro Preview Custom ToolsGPT-4o-mini Search Preview
VisionYesNo
MultimodalYesNo
ReasoningNoNo
JSON / Tool useNoNo
Structured outputsYesYes
Code executionNoNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

No shared benchmark scores are currently available for this pair.

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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.