Mistral Magistral Small 2509 vs Mistral Small 4
Mistral Magistral Small 2509 (2025) and Mistral Small 4 (2026) are general-purpose language models from MistralAI. Mistral Magistral Small 2509 ships a not-yet-sourced context window, while Mistral Small 4 ships a 256K-token context window. On pricing, Mistral Small 4 costs $0.15/1M input tokens versus $0.5/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
Mistral Small 4 is ~233% cheaper at $0.15/1M; pay for Mistral Magistral Small 2509 only for provider fit.
Decision scorecard
Local evidence first| Signal | Mistral Magistral Small 2509 | Mistral Small 4 |
|---|---|---|
| Decision fit | General | RAG, Agents, and Long context |
| Context window | — | 256K |
| Cheapest output | $1.5/1M tokens | $0.6/1M tokens |
| Provider routes | 1 tracked | 3 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- 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.
- Mistral Small 4 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Mistral Small 4 has the lower cheapest tracked output price at $0.6/1M tokens.
- Mistral Small 4 has broader tracked provider coverage for fallback and procurement flexibility.
- Mistral Small 4 uniquely exposes Vision, Multimodal, and Function calling in local model data.
- Local decision data tags Mistral Small 4 for RAG, Agents, and Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output prices on this page.
Mistral Magistral Small 2509
$775
Cheapest tracked route: AWS Bedrock
Mistral Small 4
$270
Cheapest tracked route: OpenRouter
Estimated monthly gap: $505. Batch, cache, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for Mistral Magistral Small 2509 and Mistral Small 4; plan for SDK, billing, or endpoint changes.
- Mistral Small 4 is $0.9/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Mistral Small 4 adds Vision, Multimodal, and Function calling in local capability data.
- No overlapping tracked provider route is sourced for Mistral Small 4 and Mistral Magistral Small 2509; plan for SDK, billing, or endpoint changes.
- Mistral Magistral Small 2509 is $0.9/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Vision, Multimodal, and Function calling before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-09-01 | 2026-03-16 |
| Context window | — | 256K |
| Parameters | — | 119B (6.5B active) |
| Architecture | - | moe |
| License | Proprietary | Apache 2.0 |
| Knowledge cutoff | - | 2025-06 |
Pricing and availability
| Pricing attribute | Mistral Magistral Small 2509 | Mistral Small 4 |
|---|---|---|
| Input price | $0.5/1M tokens | $0.15/1M tokens |
| Output price | $1.5/1M tokens | $0.6/1M tokens |
| Providers |
Capabilities
| Capability | Mistral Magistral Small 2509 | Mistral Small 4 |
|---|---|---|
| Vision | No | Yes |
| Multimodal | No | Yes |
| Reasoning | No | No |
| Function calling | No | Yes |
| Tool use | No | Yes |
| Structured outputs | No | No |
| Code execution | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on vision: Mistral Small 4, multimodal input: Mistral Small 4, function calling: Mistral Small 4, and tool use: Mistral Small 4. 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, Mistral Magistral Small 2509 lists $0.5/1M input and $1.5/1M output tokens, while Mistral Small 4 lists $0.15/1M input and $0.6/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Mistral Small 4 lower by about $0.51 per million blended tokens. Availability is 1 providers versus 3, so concentration risk also matters.
Choose Mistral Magistral Small 2509 when provider fit are central to the workload. Choose Mistral Small 4 when vision-heavy evaluation, lower input-token cost, and broader provider choice 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.
FAQ
Which is cheaper, Mistral Magistral Small 2509 or Mistral Small 4?
Mistral Small 4 is cheaper on tracked token pricing. Mistral Magistral Small 2509 costs $0.5/1M input and $1.5/1M output tokens. Mistral Small 4 costs $0.15/1M input and $0.6/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Mistral Magistral Small 2509 or Mistral Small 4 open source?
Mistral Magistral Small 2509 is listed under Proprietary. Mistral Small 4 is listed under Apache 2.0. 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, Mistral Magistral Small 2509 or Mistral Small 4?
Mistral Small 4 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, Mistral Magistral Small 2509 or Mistral Small 4?
Mistral Small 4 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, Mistral Magistral Small 2509 or Mistral Small 4?
Mistral Small 4 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 Mistral Magistral Small 2509 and Mistral Small 4?
Mistral Magistral Small 2509 is available on AWS Bedrock. Mistral Small 4 is available on OpenRouter, NVIDIA NIM, and Mistral AI Studio. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-19. Data sourced from public model cards and provider documentation.