DeepSeek R1 vs Mistral Magistral Small 2509
DeepSeek R1 (2025) and Mistral Magistral Small 2509 (2025) are frontier reasoning models from DeepSeek and MistralAI. DeepSeek R1 ships a 128K-token context window, while Mistral Magistral Small 2509 ships a not-yet-sourced context window. On pricing, DeepSeek R1 costs $0.1/1M input tokens versus $0.5/1M 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.
DeepSeek R1 is ~400% cheaper at $0.1/1M; pay for Mistral Magistral Small 2509 only for provider fit.
Specs
| Released | 2025-01-20 | 2025-09-01 |
| Context window | 128K | — |
| Parameters | 671B, 37B Active | — |
| Architecture | decoder only | - |
| License | Open Source | Proprietary |
| Knowledge cutoff | - | - |
Pricing and availability
| DeepSeek R1 | Mistral Magistral Small 2509 | |
|---|---|---|
| Input price | $0.1/1M tokens | $0.5/1M tokens |
| Output price | $0.3/1M tokens | $1.5/1M tokens |
| Providers |
Capabilities
| DeepSeek R1 | 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 reasoning mode: DeepSeek R1, structured outputs: DeepSeek R1, and code execution: DeepSeek R1. 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 R1 lists $0.1/1M input and $0.3/1M 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 DeepSeek R1 lower by about $0.64 per million blended tokens. Availability is 13 providers versus 1, so concentration risk also matters.
Choose DeepSeek R1 when coding workflow support, lower input-token cost, and broader provider choice are central to the workload. Choose Mistral Magistral Small 2509 when provider fit 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 R1 or Mistral Magistral Small 2509?
DeepSeek R1 is cheaper on tracked token pricing. DeepSeek R1 costs $0.1/1M input and $0.3/1M 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 R1 or Mistral Magistral Small 2509 open source?
DeepSeek R1 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 reasoning mode, DeepSeek R1 or Mistral Magistral Small 2509?
DeepSeek R1 has the clearer documented reasoning mode signal in this comparison. If reasoning mode 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 R1 or Mistral Magistral Small 2509?
DeepSeek R1 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.
Which is better for code execution, DeepSeek R1 or Mistral Magistral Small 2509?
DeepSeek R1 has the clearer documented code execution signal in this comparison. If code execution is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run DeepSeek R1 and Mistral Magistral Small 2509?
DeepSeek R1 is available on DeepSeek Platform, OpenRouter, Together AI, Fireworks AI, and NVIDIA NIM. Mistral Magistral Small 2509 is available on AWS Bedrock. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.