GPT-5 Pro vs Mistral Magistral Small 2509
GPT-5 Pro (2025) and Mistral Magistral Small 2509 (2025) are general-purpose language models from OpenAI and MistralAI. GPT-5 Pro ships a 400k-token context window, while Mistral Magistral Small 2509 ships a not-yet-sourced context window. On pricing, Mistral Magistral Small 2509 costs $0.50/1M input tokens versus $15/1M 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.
Mistral Magistral Small 2509 is ~2900% cheaper at $0.50/1M; pay for GPT-5 Pro only for coding workflow support.
Decision scorecard
Local evidence first| Signal | GPT-5 Pro | Mistral Magistral Small 2509 |
|---|---|---|
| Best for | multimodal apps, tool-calling agents, and provider-routed production | provider-routed production |
| Decision fit | Coding, RAG, and Agents | General |
| Context window | 400k | — |
| Cheapest output | $120/1M tokens | $1.50/1M tokens |
| Provider routes | 2 tracked | 2 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- GPT-5 Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-5 Pro uniquely exposes Vision, Multimodal, and Function calling in local model data.
- Local decision data tags GPT-5 Pro for Coding, RAG, and Agents.
- Mistral Magistral Small 2509 has the lower cheapest tracked output price at $1.50/1M tokens.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
GPT-5 Pro
$42,000
Cheapest tracked route/tier: Vercel AI Gateway
Mistral Magistral Small 2509
$775
Cheapest tracked route/tier: AWS Bedrock
Estimated monthly gap: $41,225. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
- Mistral Magistral Small 2509 is $119/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Multimodal, and Function calling before moving production traffic.
- Provider overlap exists on Vercel AI Gateway; start route-level A/B tests there.
- GPT-5 Pro is $119/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- GPT-5 Pro adds Vision, Multimodal, and Function calling in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-10-01 | 2025-09-01 |
| Context window | 400k | — |
| Parameters | — | 24B |
| Architecture | Decoder Only | - |
| License | Proprietary | Apache 2.0OSI-approved |
| Openness | Proprietary | Open source |
| Commercial use | Commercial use: conditional | Commercial use: permitted |
| Knowledge cutoff | 2024-09 | - |
Pricing and availability
| Pricing attribute | GPT-5 Pro | Mistral Magistral Small 2509 |
|---|---|---|
| Input price | $15/1M tokens | $0.50/1M tokens |
| Output price | $120/1M tokens | $1.50/1M tokens |
| Providers |
Capabilities
| Capability | GPT-5 Pro | Mistral Magistral Small 2509 |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | No | No |
| Function calling | Yes | No |
| Tool use | Yes | 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.
Deep dive
The capability footprint differs most on vision: GPT-5 Pro, multimodal input: GPT-5 Pro, function calling: GPT-5 Pro, tool use: GPT-5 Pro, structured outputs: GPT-5 Pro, and code execution: GPT-5 Pro. 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, GPT-5 Pro lists $15/1M input and $120/1M output tokens on the cheapest tracked provider, while Mistral Magistral Small 2509 lists $0.50/1M input and $1.50/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Mistral Magistral Small 2509 lower by about $45.70 per million blended tokens. Availability is 2 providers versus 2, so concentration risk also matters.
Choose GPT-5 Pro when coding workflow support 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.
FAQ
Which is cheaper, GPT-5 Pro or Mistral Magistral Small 2509?
Mistral Magistral Small 2509 is cheaper on tracked token pricing. GPT-5 Pro costs $15/1M input and $120/1M output tokens. Mistral Magistral Small 2509 costs $0.50/1M input and $1.50/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is GPT-5 Pro or Mistral Magistral Small 2509 open source?
GPT-5 Pro is listed under Proprietary. Mistral Magistral Small 2509 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, GPT-5 Pro or Mistral Magistral Small 2509?
GPT-5 Pro 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, GPT-5 Pro or Mistral Magistral Small 2509?
GPT-5 Pro 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, GPT-5 Pro or Mistral Magistral Small 2509?
GPT-5 Pro 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 GPT-5 Pro and Mistral Magistral Small 2509?
GPT-5 Pro is available on Vercel AI Gateway and OpenRouter. Mistral Magistral Small 2509 is available on AWS Bedrock and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.