DeepSeek V3.1 vs Mistral Magistral Small 2509
DeepSeek V3.1 (2026) and Mistral Magistral Small 2509 (2025) are compact production models from DeepSeek and MistralAI. DeepSeek V3.1 ships a 64K-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 $0.56/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
DeepSeek V3.1 is safer overall; choose Mistral Magistral Small 2509 when provider fit matters.
Specs
| Released | 2026-03-01 | 2025-09-01 |
| Context window | 64K | — |
| Parameters | — | — |
| Architecture | mixture of experts | - |
| License | Open Source | Proprietary |
| Knowledge cutoff | - | - |
Pricing and availability
| DeepSeek V3.1 | Mistral Magistral Small 2509 | |
|---|---|---|
| Input price | $0.56/1M tokens | $0.5/1M tokens |
| Output price | $1.68/1M tokens | $1.5/1M tokens |
| Providers |
Capabilities
| DeepSeek V3.1 | Mistral Magistral Small 2509 | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on vision: DeepSeek V3.1, multimodal input: DeepSeek V3.1, structured outputs: DeepSeek V3.1, and code execution: DeepSeek V3.1. 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, DeepSeek V3.1 lists $0.56/1M input and $1.68/1M 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 $0.1 per million blended tokens. Availability is 6 providers versus 1, so concentration risk also matters.
Choose DeepSeek V3.1 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, DeepSeek V3.1 or Mistral Magistral Small 2509?
Mistral Magistral Small 2509 is cheaper on tracked token pricing. DeepSeek V3.1 costs $0.56/1M input and $1.68/1M 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 DeepSeek V3.1 or Mistral Magistral Small 2509 open source?
DeepSeek V3.1 is listed under Open Source. 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, DeepSeek V3.1 or Mistral Magistral Small 2509?
DeepSeek V3.1 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, DeepSeek V3.1 or Mistral Magistral Small 2509?
DeepSeek V3.1 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 structured outputs, DeepSeek V3.1 or Mistral Magistral Small 2509?
DeepSeek V3.1 has the clearer documented structured outputs signal in this comparison. If structured outputs is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run DeepSeek V3.1 and Mistral Magistral Small 2509?
DeepSeek V3.1 is available on Microsoft Foundry, Fireworks AI, NVIDIA NIM, Together AI, and AWS Bedrock. 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: 2026-04-24. Data sourced from public model cards and provider documentation.