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Phi-4 Reasoning

Phi-4 Reasoning

Big reasoning power, small models

Website azure.microsoft.com
Overview

What it is

Small open-weight models (3.8B/14B) delivering powerful reasoning for math/science/code, rivaling larger LLMs. Available on Azure AI Foundry & HF.

Intent

I need it when

Deploy reasoning capabilities on Windows 11 Copilot+ PCs and edge devices with NPU acceleration

Phi-4 Reasoning models are optimized for Phi Silica (NPU-optimized variant) and will run on Copilot+ PC NPUs using ONNX optimization. This enables blazing-fast time-to-first-token responses and power-efficient token throughput, allowing concurrent invocation with other applications while providing offline reasoning capabilities.

Build agentic applications requiring complex, multi-faceted task decomposition without deploying massive frontier models

Phi-4 Reasoning models are positioned as the backbone of agentic applications. They balance size and performance through distillation and reinforcement learning, enabling resource-limited devices to perform complex reasoning tasks efficiently. Phi-4-reasoning-plus uses 1.5x more inference-time tokens for higher accuracy, making it suitable for sophisticated multi-step agent workflows.

Perform complex mathematical reasoning and multi-step problem solving efficiently on resource-constrained hardware

Phi-4 Reasoning is a 14B parameter open-weight model trained via supervised fine-tuning on high-quality reasoning demonstrations. It generates detailed reasoning chains leveraging inference-time compute, achieving performance comparable to much larger models (DeepSeek-R1 at 671B parameters) on AIME 2025 and other mathematical benchmarks, while remaining small enough for low-latency environments and edge deployment.

Access a compact reasoning model for educational applications and embedded tutoring systems

Phi-4-mini-reasoning is a 3.8B parameter model optimized for mathematical reasoning and step-by-step problem solving. Trained on over one million diverse math problems from middle school to Ph.D. level, it outperforms models twice its size on math benchmarks and is ideal for educational applications, embedded tutoring, and lightweight edge/mobile deployment.

Leverage open-weight models available on HuggingFace and Azure AI Foundry for customization and fine-tuning

Phi-4 Reasoning models are available as open-weight models on both Azure AI Foundry and HuggingFace, enabling users to tinker, tweak, and customize within projects. This allows organizations to fine-tune the models on proprietary data, integrate them into custom pipelines, and maintain full control over deployment without vendor lock-in.

Drop

Not a fit when

  • User requires a proprietary, closed-source model with guaranteed support contracts and SLAs
  • User needs real-time inference with sub-100ms latency on resource-constrained edge devices without optimization
  • User requires models trained exclusively on proprietary datasets without synthetic or distilled training data
  • User needs a model optimized for non-reasoning tasks like simple classification or sentiment analysis
  • User operates in an environment where open-weight models are prohibited by compliance or security policy
Commercials

Pricing

Available on Azure AI Foundry and HuggingFace; pricing depends on Azure consumption model or open-source deployment View pricing