GLM-5.1 vs Mistral Magistral Small 2509
GLM-5.1 (2026) and Mistral Magistral Small 2509 (2025) are frontier reasoning models from Zhipu AI and MistralAI. GLM-5.1 ships a 200k-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 $0.95/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
Mistral Magistral Small 2509 is ~90% cheaper at $0.5/1M; pay for GLM-5.1 only for coding workflow support.
Specs
| Released | 2026-03-27 | 2025-09-01 |
| Context window | 200k | — |
| Parameters | 744B total, 40-44B active | — |
| Architecture | mixture of experts | - |
| License | Proprietary | Proprietary |
| Knowledge cutoff | - | - |
Pricing and availability
| GLM-5.1 | Mistral Magistral Small 2509 | |
|---|---|---|
| Input price | $0.95/1M tokens | $0.5/1M tokens |
| Output price | $3.15/1M tokens | $1.5/1M tokens |
| Providers |
Capabilities
| GLM-5.1 | 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 reasoning mode: GLM-5.1, function calling: GLM-5.1, tool use: GLM-5.1, structured outputs: GLM-5.1, and code execution: GLM-5.1. 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, GLM-5.1 lists $0.95/1M input and $3.15/1M 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 $0.81 per million blended tokens. Availability is 2 providers versus 1, so concentration risk also matters.
Choose GLM-5.1 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, GLM-5.1 or Mistral Magistral Small 2509?
Mistral Magistral Small 2509 is cheaper on tracked token pricing. GLM-5.1 costs $0.95/1M input and $3.15/1M 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 GLM-5.1 or Mistral Magistral Small 2509 open source?
GLM-5.1 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 reasoning mode, GLM-5.1 or Mistral Magistral Small 2509?
GLM-5.1 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 function calling, GLM-5.1 or Mistral Magistral Small 2509?
GLM-5.1 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.
Which is better for tool use, GLM-5.1 or Mistral Magistral Small 2509?
GLM-5.1 has the clearer documented tool use signal in this comparison. If tool use is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run GLM-5.1 and Mistral Magistral Small 2509?
GLM-5.1 is available on Z.ai and OpenRouter. Mistral Magistral Small 2509 is available on AWS Bedrock. Provider coverage can affect latency, region availability, compliance posture, and fallback options. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
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Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.