GPT-4o Audio vs Mistral Magistral Small 2509
GPT-4o Audio (2024) and Mistral Magistral Small 2509 (2025) are compact production models from OpenAI and MistralAI. GPT-4o Audio ships a 128k-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 $2.50/1M 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.
Mistral Magistral Small 2509 is ~400% cheaper at $0.50/1M; pay for GPT-4o Audio only for provider fit.
Decision scorecard
Local evidence first| Signal | GPT-4o Audio | Mistral Magistral Small 2509 |
|---|---|---|
| Best for | general production evaluation | provider-routed production |
| Decision fit | Long context | General |
| Context window | 128k | — |
| Cheapest output | $10/1M tokens | $1.50/1M tokens |
| Provider routes | 1 tracked | 2 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- GPT-4o Audio has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Local decision data tags GPT-4o Audio for Long context.
- Mistral Magistral Small 2509 has the lower cheapest tracked output price at $1.50/1M tokens.
- Mistral Magistral Small 2509 has broader tracked provider coverage for fallback and procurement flexibility.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
GPT-4o Audio
$4,500
Cheapest tracked route/tier: OpenRouter
Mistral Magistral Small 2509
$775
Cheapest tracked route/tier: AWS Bedrock
Estimated monthly gap: $3,725. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for GPT-4o Audio and Mistral Magistral Small 2509; plan for SDK, billing, or endpoint changes.
- Mistral Magistral Small 2509 is $8.50/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- No overlapping tracked provider route is sourced for Mistral Magistral Small 2509 and GPT-4o Audio; plan for SDK, billing, or endpoint changes.
- GPT-4o Audio is $8.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
Specs
| Specification | ||
|---|---|---|
| Released | 2024-10-01 | 2025-09-01 |
| Context window | 128k | — |
| 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 | 2023-10 | - |
Pricing and availability
| Pricing attribute | GPT-4o Audio | Mistral Magistral Small 2509 |
|---|---|---|
| Input price | $2.50/1M tokens | $0.50/1M tokens |
| Output price | $10/1M tokens | $1.50/1M tokens |
| Providers |
Capabilities
| Capability | GPT-4o Audio | Mistral Magistral Small 2509 |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | No | No |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | No | No |
| Code execution | No | 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 is close: both models cover the core production surface. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.
For cost, GPT-4o Audio lists $2.50/1M input and $10/1M 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 $3.95 per million blended tokens. Availability is 1 providers versus 2, so concentration risk also matters.
Choose GPT-4o Audio when provider fit are central to the workload. Choose Mistral Magistral Small 2509 when provider fit, 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. It also helps separate model capability from provider packaging, which can change cost and latency.
FAQ
Which is cheaper, GPT-4o Audio or Mistral Magistral Small 2509?
Mistral Magistral Small 2509 is cheaper on tracked token pricing. GPT-4o Audio costs $2.50/1M input and $10/1M 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-4o Audio or Mistral Magistral Small 2509 open source?
GPT-4o Audio 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.
Where can I run GPT-4o Audio and Mistral Magistral Small 2509?
GPT-4o Audio is available on 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.
When should I pick GPT-4o Audio over Mistral Magistral Small 2509?
Mistral Magistral Small 2509 is ~400% cheaper at $0.50/1M; pay for GPT-4o Audio only for provider fit. If your workload also depends on provider fit, start with GPT-4o Audio; if it depends on provider fit, run the same evaluation with Mistral Magistral Small 2509.
Continue comparing
Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.