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GPT-4.1 vs Mistral Magistral Small 2509

GPT-4.1 (2025) and Mistral Magistral Small 2509 (2025) are general-purpose language models from OpenAI and MistralAI. GPT-4.1 ships a 1M-token context window, while Mistral Magistral Small 2509 ships a not-yet-sourced context window. On pricing, Mistral Magistral Small 2509 costs $0.5/1M input tokens versus $2/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing.

Mistral Magistral Small 2509 is ~300% cheaper at $0.5/1M; pay for GPT-4.1 only for coding workflow support.

Decision scorecard

Local evidence first
SignalGPT-4.1Mistral Magistral Small 2509
Decision fitCoding, RAG, and AgentsGeneral
Context window1M
Cheapest output$8/1M tokens$1.5/1M tokens
Provider routes3 tracked1 tracked
Shared benchmarks0 rows0 rows

Decision tradeoffs

Choose GPT-4.1 when...
  • GPT-4.1 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • GPT-4.1 has broader tracked provider coverage for fallback and procurement flexibility.
  • GPT-4.1 uniquely exposes Vision, Multimodal, and Function calling in local model data.
  • Local decision data tags GPT-4.1 for Coding, RAG, and Agents.
Choose Mistral Magistral Small 2509 when...
  • Mistral Magistral Small 2509 has the lower cheapest tracked output price at $1.5/1M tokens.

Monthly cost at traffic

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

Lower estimate Mistral Magistral Small 2509

GPT-4.1

$3,600

Cheapest tracked route: OpenRouter

Mistral Magistral Small 2509

$775

Cheapest tracked route: AWS Bedrock

Estimated monthly gap: $2,825. Batch, cache, and negotiated pricing are excluded from this local estimate.

Switch friction

GPT-4.1 -> Mistral Magistral Small 2509
  • No overlapping tracked provider route is sourced for GPT-4.1 and Mistral Magistral Small 2509; plan for SDK, billing, or endpoint changes.
  • Mistral Magistral Small 2509 is $6.5/1M 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 -> GPT-4.1
  • No overlapping tracked provider route is sourced for Mistral Magistral Small 2509 and GPT-4.1; plan for SDK, billing, or endpoint changes.
  • GPT-4.1 is $6.5/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • GPT-4.1 adds Vision, Multimodal, and Function calling in local capability data.

Specs

Specification
Released2025-04-012025-09-01
Context window1M
Parameters
Architecturedecoder only-
LicenseProprietaryProprietary
Knowledge cutoff2025-01-

Pricing and availability

Pricing attributeGPT-4.1Mistral Magistral Small 2509
Input price$2/1M tokens$0.5/1M tokens
Output price$8/1M tokens$1.5/1M tokens
Providers

Capabilities

CapabilityGPT-4.1Mistral Magistral Small 2509
VisionYesNo
MultimodalYesNo
ReasoningNoNo
Function callingYesNo
Tool useYesNo
Structured outputsYesNo
Code executionYesNo

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

The capability footprint differs most on vision: GPT-4.1, multimodal input: GPT-4.1, function calling: GPT-4.1, tool use: GPT-4.1, structured outputs: GPT-4.1, and code execution: GPT-4.1. 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, GPT-4.1 lists $2/1M input and $8/1M output tokens, while Mistral Magistral Small 2509 lists $0.5/1M input and $1.5/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Mistral Magistral Small 2509 lower by about $3 per million blended tokens. Availability is 3 providers versus 1, so concentration risk also matters.

Choose GPT-4.1 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. 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 is cheaper, GPT-4.1 or Mistral Magistral Small 2509?

Mistral Magistral Small 2509 is cheaper on tracked token pricing. GPT-4.1 costs $2/1M input and $8/1M output tokens. Mistral Magistral Small 2509 costs $0.5/1M input and $1.5/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is GPT-4.1 or Mistral Magistral Small 2509 open source?

GPT-4.1 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, GPT-4.1 or Mistral Magistral Small 2509?

GPT-4.1 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. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Which is better for multimodal input, GPT-4.1 or Mistral Magistral Small 2509?

GPT-4.1 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, GPT-4.1 or Mistral Magistral Small 2509?

GPT-4.1 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 GPT-4.1 and Mistral Magistral Small 2509?

GPT-4.1 is available on OpenRouter, Azure OpenAI, and OpenAI API. Mistral Magistral Small 2509 is available on AWS Bedrock. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-11. Data sourced from public model cards and provider documentation.