LLM Reference

Gemini 3.1 Pro Preview vs Mistral Magistral Small 2509

Gemini 3.1 Pro Preview (2026) and Mistral Magistral Small 2509 (2025) are general-purpose language models from Google DeepMind and MistralAI. Gemini 3.1 Pro Preview ships a 1M-token context window, while Mistral Magistral Small 2509 ships a not-yet-sourced context window. On pricing, Gemini 3.1 Pro Preview ranges from $2 to $4/1M input tokens by tier; Mistral Magistral Small 2509 costs $0.50/1M input tokens. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.

Gemini 3.1 Pro Preview is safer overall; choose Mistral Magistral Small 2509 when provider fit matters.

Decision scorecard

Local evidence first
SignalGemini 3.1 Pro PreviewMistral Magistral Small 2509
Best formultimodal apps, tool-calling agents, and long-context analysisprovider-routed production
Decision fitCoding, RAG, and AgentsGeneral
Context window1M
Cheapest output$12/1M tokens$1.50/1M tokens
Provider routes5 tracked2 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 Vision, Multimodal, and Function calling in local model data.
  • Local decision data tags Gemini 3.1 Pro Preview for Coding, RAG, and Agents.
Choose Mistral Magistral Small 2509 when...
  • Mistral Magistral Small 2509 has the lower cheapest tracked output price at $1.50/1M tokens.

Monthly cost at traffic

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

Lower estimate Mistral Magistral Small 2509

Gemini 3.1 Pro Preview

$4,600

Cheapest tracked route/tier: Google AI Studio

Mistral Magistral Small 2509

$775

Cheapest tracked route/tier: AWS Bedrock

Estimated monthly gap: $3,825. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Gemini 3.1 Pro Preview -> Mistral Magistral Small 2509
  • Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
  • Mistral Magistral Small 2509 is $10.50/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Vision, Multimodal, and Function calling before moving production traffic.
Mistral Magistral Small 2509 -> Gemini 3.1 Pro Preview
  • Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
  • Gemini 3.1 Pro Preview is $10.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Gemini 3.1 Pro Preview adds Vision, Multimodal, and Function calling in local capability data.

Specs

Specification
Released2026-02-192025-09-01
Context window1M
Parameters24B
Architecturedecoder only-
LicenseProprietaryProprietary
Knowledge cutoff2025-01-

Pricing and availability

Pricing attributeGemini 3.1 Pro PreviewMistral Magistral Small 2509
Input price
0-200,001t
$2/1M tokens
200,001t+
$4/1M tokens
$0.50/1M tokens
Output price
0-200,001t
$12/1M tokens
200,001t+
$18/1M tokens
$1.50/1M tokens
Providers

Capabilities

CapabilityGemini 3.1 Pro PreviewMistral Magistral Small 2509
VisionYesNo
MultimodalYesNo
ReasoningNoNo
Function callingYesNo
Tool useYesNo
Structured outputsYesNo
Code executionYesNo
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, multimodal input: Gemini 3.1 Pro Preview, function calling: Gemini 3.1 Pro Preview, tool use: Gemini 3.1 Pro Preview, structured outputs: Gemini 3.1 Pro Preview, and code execution: Gemini 3.1 Pro Preview. Both models share the core language-model surface, 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 tiered pricing: 0-200,001t is $2/1M input and $12/1M output; 200,001t+ is $4/1M input and $18/1M output, while Mistral Magistral Small 2509 lists $0.50/1M input and $1.50/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Mistral Magistral Small 2509 lower by about $4.20 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 5 providers versus 2, so concentration risk also matters.

Choose Gemini 3.1 Pro Preview when coding workflow support and broader provider choice are central to the workload. Choose Mistral Magistral Small 2509 when provider fit and lower input-token cost are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.

FAQ

Which is cheaper, Gemini 3.1 Pro Preview or Mistral Magistral Small 2509?

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. Mistral Magistral Small 2509 lists $0.50/1M input and $1.50/1M output tokens on the cheapest tracked provider. 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 3.1 Pro Preview or Mistral Magistral Small 2509 open source?

Gemini 3.1 Pro Preview is listed under Proprietary. Mistral Magistral Small 2509 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 Mistral Magistral Small 2509?

Gemini 3.1 Pro Preview 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 or Mistral Magistral Small 2509?

Gemini 3.1 Pro Preview 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.

Which is better for function calling, Gemini 3.1 Pro Preview or Mistral Magistral Small 2509?

Gemini 3.1 Pro Preview has the clearer documented function calling signal in this comparison. If function calling 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 and Mistral Magistral Small 2509?

Gemini 3.1 Pro Preview is available on Google AI Studio, GCP Vertex AI, OpenRouter, Replicate API, and Vercel AI Gateway. Mistral Magistral Small 2509 is available on AWS Bedrock 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.