Mistral Small 4 vs Phi-4 Mini Reasoning
Mistral Small 4 (2026) and Phi-4 Mini Reasoning (2026) are frontier reasoning models from MistralAI and Microsoft Research. Mistral Small 4 ships a 256k-token context window, while Phi-4 Mini Reasoning ships a 128k-token context window. On Google-Proof Q&A, Mistral Small 4 leads by 24.9 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Phi-4 Mini Reasoning is safer overall; choose Mistral Small 4 when long-context analysis matters.
Decision scorecard
Local evidence first| Signal | Mistral Small 4 | Phi-4 Mini Reasoning |
|---|---|---|
| Best for | multimodal apps, tool-calling agents, and provider-routed production | reasoning-heavy apps |
| Decision fit | RAG, Agents, and Long context | Long context |
| Context window | 256k | 128k |
| Cheapest output | $0.60/1M tokens | - |
| Provider routes | 3 tracked | 0 tracked |
| Shared benchmarks | Google-Proof Q&A leader | 1 rows |
Decision tradeoffs
- Mistral Small 4 holds a shared-benchmark lead on Google-Proof Q&A, ahead by 24.9 points.
- Mistral Small 4 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Mistral Small 4 has broader tracked provider coverage for fallback and procurement flexibility.
- Mistral Small 4 uniquely exposes Vision, Multimodal, and Function calling in local model data.
- Local decision data tags Mistral Small 4 for RAG, Agents, and Long context.
- Phi-4 Mini Reasoning uniquely exposes Reasoning in local model data.
- Local decision data tags Phi-4 Mini 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 Small 4
$270
Cheapest tracked route/tier: OpenRouter
Phi-4 Mini 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 Small 4 and Phi-4 Mini Reasoning; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Vision, Multimodal, and Function calling before moving production traffic.
- Phi-4 Mini Reasoning adds Reasoning in local capability data.
- No overlapping tracked provider route is sourced for Phi-4 Mini Reasoning and Mistral Small 4; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Reasoning before moving production traffic.
- Mistral Small 4 adds Vision, Multimodal, and Function calling in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-03-16 | 2026-05-16 |
| Context window | 256k | 128k |
| Parameters | 119B (6.5B active) | 3.8B |
| Architecture | moe | - |
| License | Apache 2.0(OSI) | MIT(OSI) |
| Openness | Open source | Open source |
| Commercial use | Commercial use allowed | Commercial use allowed |
| Knowledge cutoff | 2025-06 | 2025-02 |
Pricing and availability
| Pricing attribute | Mistral Small 4 | Phi-4 Mini Reasoning |
|---|---|---|
| Input price | $0.15/1M tokens | - |
| Output price | $0.60/1M tokens | - |
| Providers | - |
Capabilities
| Capability | Mistral Small 4 | Phi-4 Mini Reasoning |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | No | Yes |
| Function calling | Yes | No |
| Tool use | Yes | No |
| Structured outputs | No | No |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Mistral Small 4 | Phi-4 Mini Reasoning |
|---|---|---|
| Google-Proof Q&A | 76.9 | 52.0 |
Deep dive
On shared benchmark coverage, Google-Proof Q&A has Mistral Small 4 at 76.9 and Phi-4 Mini Reasoning at 52, with Mistral Small 4 ahead by 24.9 points. The largest visible gap is 24.9 points on Google-Proof Q&A, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on vision: Mistral Small 4, multimodal input: Mistral Small 4, reasoning mode: Phi-4 Mini Reasoning, function calling: Mistral Small 4, and tool use: Mistral Small 4. 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.
Pricing coverage is uneven: Mistral Small 4 has $0.15/1M input tokens and Phi-4 Mini Reasoning has no token price sourced yet. Provider availability is 3 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 Small 4 when long-context analysis, larger context windows, and broader provider choice are central to the workload. Choose Phi-4 Mini Reasoning when reasoning depth are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Mistral Small 4 or Phi-4 Mini Reasoning?
Mistral Small 4 supports 256k tokens, while Phi-4 Mini 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 Small 4 or Phi-4 Mini Reasoning open source?
Mistral Small 4 is listed under Apache 2.0. Phi-4 Mini 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 Small 4 or Phi-4 Mini Reasoning?
Mistral Small 4 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 Small 4 or Phi-4 Mini Reasoning?
Mistral Small 4 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 Small 4 or Phi-4 Mini Reasoning?
Phi-4 Mini Reasoning 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.
Where can I run Mistral Small 4 and Phi-4 Mini Reasoning?
Mistral Small 4 is available on OpenRouter, NVIDIA NIM, and Mistral AI Studio. Phi-4 Mini Reasoning is available on the tracked providers still being sourced. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-22. Data sourced from public model cards and provider documentation.