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Mistral Medium 3.5 vs Phi-4 Reasoning Vision 15B

Mistral Medium 3.5 (2026) and Phi-4 Reasoning Vision 15B (2026) are frontier reasoning models from MistralAI and Microsoft Research. Mistral Medium 3.5 ships a 256K-token context window, while Phi-4 Reasoning Vision 15B ships a not-yet-sourced context window. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing.

Mistral Medium 3.5 is safer overall; choose Phi-4 Reasoning Vision 15B when provider fit matters.

Specs

Specification
Released2026-04-292026-03-12
Context window256K
Parameters128B15B
Architecturedecoder only-
LicenseMistral LicenseMicrosoft Research
Knowledge cutoff--

Pricing and availability

Pricing attributeMistral Medium 3.5Phi-4 Reasoning Vision 15B
Input price$1.5/1M tokens-
Output price$7.5/1M tokens-
Providers-

Capabilities

CapabilityMistral Medium 3.5Phi-4 Reasoning Vision 15B
VisionYesNo
MultimodalYesYes
ReasoningYesNo
Function callingYesNo
Tool useYesNo
Structured outputsYesNo
Code executionNoNo

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

The capability footprint differs most on vision: Mistral Medium 3.5, reasoning mode: 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 multimodal input, 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 $1.5/1M input tokens and Phi-4 Reasoning Vision 15B has no token price sourced yet. Provider availability is 1 tracked routes versus 0. 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 reasoning depth and broader provider choice are central to the workload. Choose Phi-4 Reasoning Vision 15B 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

Is Mistral Medium 3.5 or Phi-4 Reasoning Vision 15B open source?

Mistral Medium 3.5 is listed under Mistral License. Phi-4 Reasoning Vision 15B is listed under Microsoft Research. 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 Reasoning Vision 15B?

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 Reasoning Vision 15B?

Both Mistral Medium 3.5 and Phi-4 Reasoning Vision 15B expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.

Which is better for reasoning mode, Mistral Medium 3.5 or Phi-4 Reasoning Vision 15B?

Mistral Medium 3.5 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, Mistral Medium 3.5 or Phi-4 Reasoning Vision 15B?

Mistral Medium 3.5 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 Medium 3.5 and Phi-4 Reasoning Vision 15B?

Mistral Medium 3.5 is available on Mistral AI Studio. Phi-4 Reasoning Vision 15B is available on the tracked providers still being sourced. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

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Last reviewed: 2026-05-05. Data sourced from public model cards and provider documentation.