LLM Reference

Gemini 3.1 Pro Preview Custom Tools vs GPT-4o (2024-11-20)

Gemini 3.1 Pro Preview Custom Tools (2026) and GPT-4o (2024-11-20) (2024) 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 (2024-11-20) ships a 128k-token context window. On pricing, Gemini 3.1 Pro Preview Custom Tools costs $2/1M input tokens versus $2.50/1M 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.

Gemini 3.1 Pro Preview Custom Tools fits 8x more tokens; pick it for long-context work and GPT-4o (2024-11-20) for tighter calls.

Decision scorecard

Local evidence first
SignalGemini 3.1 Pro Preview Custom ToolsGPT-4o (2024-11-20)
Best formultimodal apps and long-context analysisprovider-routed production
Decision fitRAG, Long context, and VisionCoding, RAG, and Long context
Context window1m128k
Cheapest output$12/1M tokens$10/1M tokens
Provider routes1 tracked2 tracked
Shared benchmarks0 rows0 rows

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 (2024-11-20) when...
  • GPT-4o (2024-11-20) has the lower cheapest tracked output price at $10/1M tokens.
  • GPT-4o (2024-11-20) has broader tracked provider coverage for fallback and procurement flexibility.
  • Local decision data tags GPT-4o (2024-11-20) for Coding, RAG, and Long context.

Monthly cost at traffic

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

Lower estimate GPT-4o (2024-11-20)

Gemini 3.1 Pro Preview Custom Tools

$4,600

Cheapest tracked route/tier: OpenRouter

GPT-4o (2024-11-20)

$4,500

Cheapest tracked route/tier: OpenRouter

Estimated monthly gap: $100. 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 (2024-11-20)
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • GPT-4o (2024-11-20) is $2/1M 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 (2024-11-20) -> 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 $2/1M 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
Released2026-01-012024-11-20
Context window1m128k
Parameters
Architecturedecoder onlydecoder only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
Commercial useCommercial use with conditionsCommercial use with conditions
Knowledge cutoff2025-012023-10

Pricing and availability

Pricing attributeGemini 3.1 Pro Preview Custom ToolsGPT-4o (2024-11-20)
Input price$2/1M tokens$2.50/1M tokens
Output price$12/1M tokens$10/1M tokens
Providers

Capabilities

CapabilityGemini 3.1 Pro Preview Custom ToolsGPT-4o (2024-11-20)
VisionYesNo
MultimodalYesNo
ReasoningNoNo
Function callingNoNo
Tool useNoNo
Structured outputsYesYes
Code executionNoNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

The capability footprint differs most on vision: Gemini 3.1 Pro Preview Custom Tools and multimodal input: Gemini 3.1 Pro Preview Custom Tools. Both models share structured outputs, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.

For cost, Gemini 3.1 Pro Preview Custom Tools lists $2/1M input and $12/1M output tokens on the cheapest tracked provider, while GPT-4o (2024-11-20) lists $2.50/1M input and $10/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts GPT-4o (2024-11-20) lower by about $0.25 per million blended tokens. Availability is 1 providers versus 2, so concentration risk also matters.

Choose Gemini 3.1 Pro Preview Custom Tools when long-context analysis, larger context windows, and lower input-token cost are central to the workload. Choose GPT-4o (2024-11-20) when provider fit and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions.

FAQ

Which has a larger context window, Gemini 3.1 Pro Preview Custom Tools or GPT-4o (2024-11-20)?

Gemini 3.1 Pro Preview Custom Tools supports 1m tokens, while GPT-4o (2024-11-20) supports 128k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.

Which is cheaper, Gemini 3.1 Pro Preview Custom Tools or GPT-4o (2024-11-20)?

GPT-4o (2024-11-20) is cheaper on tracked token pricing. Gemini 3.1 Pro Preview Custom Tools costs $2/1M input and $12/1M output tokens. GPT-4o (2024-11-20) costs $2.50/1M input and $10/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is Gemini 3.1 Pro Preview Custom Tools or GPT-4o (2024-11-20) open source?

Gemini 3.1 Pro Preview Custom Tools is listed under Proprietary. GPT-4o (2024-11-20) is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.

Which is better for vision, Gemini 3.1 Pro Preview Custom Tools or GPT-4o (2024-11-20)?

Gemini 3.1 Pro Preview Custom Tools has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.

Which is better for multimodal input, Gemini 3.1 Pro Preview Custom Tools or GPT-4o (2024-11-20)?

Gemini 3.1 Pro Preview Custom Tools has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.

Where can I run Gemini 3.1 Pro Preview Custom Tools and GPT-4o (2024-11-20)?

Gemini 3.1 Pro Preview Custom Tools is available on OpenRouter. GPT-4o (2024-11-20) is available on OpenRouter and OpenAI API. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-06-04. Data sourced from public model cards and provider documentation.