DeepSeek V3.1 vs Mistral Magistral Small 2509
DeepSeek V3.1 (2025) 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, DeepSeek V3.1 costs $0.27/1M input tokens versus $0.50/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
DeepSeek V3.1 is ~85% cheaper at $0.27/1M; pay for Mistral Magistral Small 2509 only for provider fit.
Decision scorecard
Local evidence first| Signal | DeepSeek V3.1 | Mistral Magistral Small 2509 |
|---|---|---|
| Best for | multimodal apps and provider-routed production | provider-routed production |
| Decision fit | Coding, Agents, and Vision | General |
| Context window | 64k | — |
| Cheapest output | $1/1M tokens | $1.50/1M tokens |
| Provider routes | 8 tracked | 2 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- DeepSeek V3.1 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- DeepSeek V3.1 has the lower cheapest tracked output price at $1/1M tokens.
- DeepSeek V3.1 has broader tracked provider coverage for fallback and route flexibility.
- DeepSeek V3.1 uniquely exposes Vision, Multimodal, and Structured outputs in local model data.
- Local decision data tags DeepSeek V3.1 for Coding, Agents, and Vision.
- Use Mistral Magistral Small 2509 when your own prompt tests beat the comparison signals; the local data does not show a decisive standalone advantage yet.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
DeepSeek V3.1
$466
Cheapest tracked route/tier: Novita AI
Mistral Magistral Small 2509
$775
Cheapest tracked route/tier: AWS Bedrock
Estimated monthly gap: $309. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on AWS Bedrock and Vercel AI Gateway; start route-level A/B tests there.
- Mistral Magistral Small 2509 is $0.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Vision, Multimodal, and Structured outputs before moving production traffic.
- Provider overlap exists on AWS Bedrock and Vercel AI Gateway; start route-level A/B tests there.
- DeepSeek V3.1 is $0.50/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- DeepSeek V3.1 adds Vision, Multimodal, and Structured outputs in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-08-21 | 2025-09-01 |
| Context window | 64k | — |
| Parameters | 671B total, 37B active (MoE) | 24B |
| Architecture | Mixture of Experts | - |
| License | MITOSI-approved | Apache 2.0OSI-approved |
| Openness | Open source | Open source |
| Weights | Unknown | Unknown |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: permitted | Commercial use: permitted |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | DeepSeek V3.1 | Mistral Magistral Small 2509 |
|---|---|---|
| Input price | $0.27/1M tokens | $0.50/1M tokens |
| Output price | $1/1M tokens | $1.50/1M tokens |
| Providers |
Capabilities
| Capability | DeepSeek V3.1 | Mistral Magistral Small 2509 |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | No | No |
| JSON / Tool use | No | No |
| Structured outputs | Yes | No |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.