LLM Reference

Gemini 3 Pro vs Gemini 3.1 Pro Preview

Gemini 3 Pro (2025) and Gemini 3.1 Pro Preview (2026) are general-purpose language models from Google DeepMind. Gemini 3 Pro ships a 1m-token context window, while Gemini 3.1 Pro Preview ships a 1m-token context window. On SWE-bench Verified, Gemini 3.1 Pro Preview leads by 4.4 pts. 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 is safer overall; choose Gemini 3 Pro when coding workflow support matters.

Decision scorecard

Local evidence first
SignalGemini 3 ProGemini 3.1 Pro Preview
Best formultimodal apps, tool-calling agents, and long-context analysismultimodal apps, tool-calling agents, and long-context analysis
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window1m1m
Cheapest output$5/1M tokens$12/1M tokens
Provider routes2 tracked5 tracked
Shared benchmarks4 rowsSWE-bench Verified leader

Decision tradeoffs

Choose Gemini 3 Pro when...
  • Gemini 3 Pro has the lower cheapest tracked output price at $5/1M tokens.
  • Local decision data tags Gemini 3 Pro for Coding, RAG, and Agents.
Choose Gemini 3.1 Pro Preview when...
  • Gemini 3.1 Pro Preview leads the largest shared benchmark signal on SWE-bench Verified by 4.4 points.
  • Gemini 3.1 Pro Preview has broader tracked provider coverage for fallback and procurement flexibility.
  • Gemini 3.1 Pro Preview uniquely exposes Structured outputs in local model data.
  • Local decision data tags Gemini 3.1 Pro Preview for Coding, RAG, and Agents.

Monthly cost at traffic

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

Lower estimate Gemini 3 Pro

Gemini 3 Pro

$2,250

Cheapest tracked route/tier: GCP Vertex AI

Gemini 3.1 Pro Preview

$4,600

Cheapest tracked route/tier: Google AI Studio

Estimated monthly gap: $2,350. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Gemini 3 Pro -> Gemini 3.1 Pro Preview
  • Provider overlap exists on GCP Vertex AI and Replicate API; start route-level A/B tests there.
  • Gemini 3.1 Pro Preview is $7/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Gemini 3.1 Pro Preview adds Structured outputs in local capability data.
Gemini 3.1 Pro Preview -> Gemini 3 Pro
  • Provider overlap exists on Replicate API and GCP Vertex AI; start route-level A/B tests there.
  • Gemini 3 Pro is $7/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Structured outputs before moving production traffic.

Specs

Specification
Released2025-12-112026-02-19
Context window1m1m
Parameters
Architecturedecoder onlydecoder only
LicenseProprietaryProprietary
Knowledge cutoff2025-012025-01

Pricing and availability

Pricing attributeGemini 3 ProGemini 3.1 Pro Preview
Input price$1.25/1M tokens
0-200,001t
$2/1M tokens
200,001t+
$4/1M tokens
Output price$5/1M tokens
0-200,001t
$12/1M tokens
200,001t+
$18/1M tokens
Providers

Capabilities

CapabilityGemini 3 ProGemini 3.1 Pro Preview
VisionYesYes
MultimodalYesYes
ReasoningNoNo
Function callingYesYes
Tool useYesYes
Structured outputsNoYes
Code executionYesYes
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkGemini 3 ProGemini 3.1 Pro Preview
SWE-bench Verified76.280.6
Google-Proof Q&A91.994.3
SWE-bench Pro42.554.2
Chatbot Arena1486.01493.0

Deep dive

On shared benchmark coverage, SWE-bench Verified has Gemini 3 Pro at 76.2 and Gemini 3.1 Pro Preview at 80.6, with Gemini 3.1 Pro Preview ahead by 4.4 points; Google-Proof Q&A has Gemini 3 Pro at 91.9 and Gemini 3.1 Pro Preview at 94.3, with Gemini 3.1 Pro Preview ahead by 2.4 points; SWE-bench Pro has Gemini 3 Pro at 42.5 and Gemini 3.1 Pro Preview at 54.2, with Gemini 3.1 Pro Preview ahead by 11.7 points. The largest visible gap is 11.7 points on SWE-bench Pro, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.

The capability footprint differs most on structured outputs: Gemini 3.1 Pro Preview. Both models share vision, multimodal input, function calling, and tool use, 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 Pro lists $1.25/1M input and $5/1M output tokens on the cheapest tracked provider, while Gemini 3.1 Pro Preview lists tiered pricing: 0-200,001t is $2/1M input and $12/1M output; 200,001t+ is $4/1M input and $18/1M output. A 70/30 input-output blend puts Gemini 3 Pro lower by about $2.63 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 2 providers versus 5, so concentration risk also matters.

Choose Gemini 3 Pro when coding workflow support and lower input-token cost are central to the workload. Choose Gemini 3.1 Pro Preview when coding workflow support 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.

FAQ

Which has a larger context window, Gemini 3 Pro or Gemini 3.1 Pro Preview?

Gemini 3 Pro supports 1m tokens, while Gemini 3.1 Pro Preview supports 1m 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 Pro or Gemini 3.1 Pro Preview?

Gemini 3 Pro lists $1.25/1M input and $5/1M output tokens on the cheapest tracked provider. Gemini 3.1 Pro Preview lists tiered pricing: 0-200,001t is $2/1M input and $12/1M output; 200,001t+ is $4/1M input and $18/1M output. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. Provider discounts or batch pricing can still change the final bill.

Is Gemini 3 Pro or Gemini 3.1 Pro Preview open source?

Gemini 3 Pro is listed under Proprietary. Gemini 3.1 Pro Preview 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 Pro or Gemini 3.1 Pro Preview?

Both Gemini 3 Pro and Gemini 3.1 Pro Preview 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 Pro or Gemini 3.1 Pro Preview?

Both Gemini 3 Pro and Gemini 3.1 Pro Preview 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 Pro and Gemini 3.1 Pro Preview?

Gemini 3 Pro is available on Replicate API and GCP Vertex AI. Gemini 3.1 Pro Preview is available on Google AI Studio, GCP Vertex AI, OpenRouter, Replicate API, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-22. Data sourced from public model cards and provider documentation.