Mistral Medium 3.5 vs Phi-4 Mini Flash Reasoning
Mistral Medium 3.5 (2026) and Phi-4 Mini Flash Reasoning (2025) are frontier-tier reasoning models from MistralAI and Microsoft Research. Mistral Medium 3.5 ships a 262k-token context window, while Phi-4 Mini Flash Reasoning ships a 128k-token context window. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads. It focuses on practical selection signals rather than broad model-family marketing.
Mistral Medium 3.5 is safer overall; choose Phi-4 Mini Flash Reasoning when provider fit matters.
Decision scorecard
Local evidence first| Signal | Mistral Medium 3.5 | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps |
| Decision fit | Coding, RAG, and Agents | Long context |
| Context window | 262k | 128k |
| Cheapest output | $7.50/1M tokens | - |
| Provider routes | 3 tracked | 1 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Mistral Medium 3.5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Mistral Medium 3.5 has broader tracked provider coverage for fallback and procurement flexibility.
- Mistral Medium 3.5 uniquely exposes Vision, Multimodal, and Function calling in local model data.
- Local decision data tags Mistral Medium 3.5 for Coding, RAG, and Agents.
- Local decision data tags Phi-4 Mini Flash Reasoning for Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Mistral Medium 3.5
$3,075
Cheapest tracked route/tier: Mistral AI Studio
Phi-4 Mini Flash Reasoning
Unavailable
No complete token price in local provider data
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- No overlapping tracked provider route is sourced for Mistral Medium 3.5 and Phi-4 Mini Flash Reasoning; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Vision, Multimodal, and Function calling before moving production traffic.
- No overlapping tracked provider route is sourced for Phi-4 Mini Flash Reasoning and Mistral Medium 3.5; plan for SDK, billing, or endpoint changes.
- Mistral Medium 3.5 adds Vision, Multimodal, and Function calling in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-04-29 | 2025-12-01 |
| Context window | 262k | 128k |
| Parameters | 128B | 3.8B |
| Architecture | Decoder Only | Decoder Only |
| License | Mistral Modified MIT License | MITOSI-approved |
| Openness | Open weights | Open source |
| Commercial use | Commercial use: conditional | Commercial use: permitted |
| Knowledge cutoff | - | 2025-02 |
Pricing and availability
| Pricing attribute | Mistral Medium 3.5 | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Input price | $1.50/1M tokens | - |
| Output price | $7.50/1M tokens | - |
| Providers |
Capabilities
| Capability | Mistral Medium 3.5 | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | Yes |
| Function calling | Yes | No |
| Tool use | Yes | No |
| Structured outputs | Yes | 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 differs most on vision: Mistral Medium 3.5, multimodal input: Mistral Medium 3.5, function calling: Mistral Medium 3.5, tool use: Mistral Medium 3.5, and structured outputs: Mistral Medium 3.5. Both models share reasoning mode, 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.
Pricing coverage is uneven: Mistral Medium 3.5 has $1.50/1M input tokens and Phi-4 Mini Flash Reasoning has no token price sourced yet. Provider availability is 3 tracked routes versus 1. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose Mistral Medium 3.5 when long-context analysis, larger context windows, and broader provider choice are central to the workload. Choose Phi-4 Mini Flash Reasoning when provider fit 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 has a larger context window, Mistral Medium 3.5 or Phi-4 Mini Flash Reasoning?
Mistral Medium 3.5 supports 262k tokens, while Phi-4 Mini Flash Reasoning supports 128k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is Mistral Medium 3.5 or Phi-4 Mini Flash Reasoning open source?
Mistral Medium 3.5 is listed under Mistral Modified MIT License. Phi-4 Mini Flash Reasoning is listed under MIT. 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 Medium 3.5 or Phi-4 Mini Flash Reasoning?
Mistral Medium 3.5 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 Medium 3.5 or Phi-4 Mini Flash Reasoning?
Mistral Medium 3.5 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 reasoning mode, Mistral Medium 3.5 or Phi-4 Mini Flash Reasoning?
Both Mistral Medium 3.5 and Phi-4 Mini Flash Reasoning expose reasoning mode. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Mistral Medium 3.5 and Phi-4 Mini Flash Reasoning?
Mistral Medium 3.5 is available on Mistral AI Studio, OpenRouter, and Vercel AI Gateway. Phi-4 Mini Flash Reasoning is available on NVIDIA NIM. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-06-19. Data sourced from public model cards and provider documentation.