LLM Reference

Gemini 3.1 Pro Preview vs GPT-4o (08-06)

Gemini 3.1 Pro Preview (2026) and GPT-4o (08-06) (2024) are compact production models from Google DeepMind and OpenAI. Gemini 3.1 Pro Preview ships a 1M-token context window, while GPT-4o (08-06) ships a 128K-token context window. On pricing, Gemini 3.1 Pro Preview costs $2/1M input tokens versus $2.5/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.

Gemini 3.1 Pro Preview fits 8x more tokens; pick it for long-context work and GPT-4o (08-06) for tighter calls.

Decision scorecard

Local evidence first
SignalGemini 3.1 Pro PreviewGPT-4o (08-06)
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window1M128K
Cheapest output$12/1M tokens$10/1M tokens
Provider routes4 tracked3 tracked
Shared benchmarks0 rows0 rows

Decision tradeoffs

Choose Gemini 3.1 Pro Preview when...
  • Gemini 3.1 Pro Preview has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Gemini 3.1 Pro Preview has broader tracked provider coverage for fallback and procurement flexibility.
  • Gemini 3.1 Pro Preview uniquely exposes Function calling and Tool use in local model data.
  • Local decision data tags Gemini 3.1 Pro Preview for Coding, RAG, and Agents.
Choose GPT-4o (08-06) when...
  • GPT-4o (08-06) has the lower cheapest tracked output price at $10/1M tokens.
  • Local decision data tags GPT-4o (08-06) for Coding, RAG, and Agents.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output prices on this page.

Lower estimate GPT-4o (08-06)

Gemini 3.1 Pro Preview

$4,600

Cheapest tracked route: Google AI Studio

GPT-4o (08-06)

$4,500

Cheapest tracked route: OpenAI API

Estimated monthly gap: $100. Batch, cache, and negotiated pricing are excluded from this local estimate.

Switch friction

Gemini 3.1 Pro Preview -> GPT-4o (08-06)
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • GPT-4o (08-06) is $2/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Function calling and Tool use before moving production traffic.
GPT-4o (08-06) -> Gemini 3.1 Pro Preview
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • Gemini 3.1 Pro Preview is $2/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Gemini 3.1 Pro Preview adds Function calling and Tool use in local capability data.

Specs

Specification
Released2026-02-192024-08-06
Context window1M128K
Parameters1.76T (8x222B MoE)*
Architecturedecoder onlymixture of experts
LicenseProprietaryProprietary
Knowledge cutoff2025-012023-10

Pricing and availability

Pricing attributeGemini 3.1 Pro PreviewGPT-4o (08-06)
Input price$2/1M tokens$2.5/1M tokens
Output price$12/1M tokens$10/1M tokens
Providers

Capabilities

CapabilityGemini 3.1 Pro PreviewGPT-4o (08-06)
VisionYesYes
MultimodalYesYes
ReasoningNoNo
Function callingYesNo
Tool useYesNo
Structured outputsYesYes
Code executionYesYes

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

The capability footprint differs most on function calling: Gemini 3.1 Pro Preview and tool use: Gemini 3.1 Pro Preview. Both models share vision, multimodal input, structured outputs, and code execution, 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 lists $2/1M input and $12/1M output tokens, while GPT-4o (08-06) lists $2.5/1M input and $10/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts GPT-4o (08-06) lower by about $0.25 per million blended tokens. Availability is 4 providers versus 3, so concentration risk also matters.

Choose Gemini 3.1 Pro Preview when coding workflow support, larger context windows, and lower input-token cost are central to the workload. Choose GPT-4o (08-06) when coding workflow support 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. It also helps separate model capability from provider packaging, which can change cost and latency.

FAQ

Which has a larger context window, Gemini 3.1 Pro Preview or GPT-4o (08-06)?

Gemini 3.1 Pro Preview supports 1M tokens, while GPT-4o (08-06) 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 or GPT-4o (08-06)?

Gemini 3.1 Pro Preview is cheaper on tracked token pricing. Gemini 3.1 Pro Preview costs $2/1M input and $12/1M output tokens. GPT-4o (08-06) costs $2.5/1M input and $10/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is Gemini 3.1 Pro Preview or GPT-4o (08-06) open source?

Gemini 3.1 Pro Preview is listed under Proprietary. GPT-4o (08-06) 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 or GPT-4o (08-06)?

Both Gemini 3.1 Pro Preview and GPT-4o (08-06) expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.

Which is better for multimodal input, Gemini 3.1 Pro Preview or GPT-4o (08-06)?

Both Gemini 3.1 Pro Preview and GPT-4o (08-06) expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.

Where can I run Gemini 3.1 Pro Preview and GPT-4o (08-06)?

Gemini 3.1 Pro Preview is available on Google AI Studio, GCP Vertex AI, OpenRouter, and Replicate API. GPT-4o (08-06) is available on OpenAI API, Salesforce Einstein Generative AI, and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-19. Data sourced from public model cards and provider documentation.