OpenAI: GPT-5.5 Pro vs Microsoft: Phi 4

Side-by-side comparison — pricing, context window, capabilities, and live leaderboard data.

Key differences

  • OpenAI: GPT-5.5 Pro has a 1050K-token context window — 64.1× larger than Microsoft: Phi 4's 16K.
  • Microsoft: Phi 4 is 100% cheaper per 1K input tokens than OpenAI: GPT-5.5 Pro ($0.0001 vs $0.0300).
  • OpenAI: GPT-5.5 Pro is built by OpenAI; Microsoft: Phi 4 is built by Microsoft.
  • OpenAI: GPT-5.5 Pro supports vision (image inputs); the other does not.

Specifications

OpenAI: GPT-5.5 ProMicrosoft: Phi 4
ProviderOpenAIMicrosoft
Context window1050K16K
Max output tokens81928192
Input price / 1K tokens$0.0300$0.0001
Output price / 1K tokens$0.1800$0.0001
Vision supportYesNo
Function callingNoNo
LicenseProprietaryProprietary

About OpenAI: GPT-5.5 Pro

US·Closed

GPT-5.5 Pro is OpenAI’s high-capability model optimized for deep reasoning and accuracy on complex, high-stakes workloads. It features a 1M+ token context window (922K input, 128K output) with support for...

View OpenAI: GPT-5.5 Pro reliability and benchmark history →

About Microsoft: Phi 4

US·Closed

[Microsoft Research](/microsoft) Phi-4 is designed to perform well in complex reasoning tasks and can operate efficiently in situations with limited memory or where quick responses are needed. At 14 billion...

View Microsoft: Phi 4 reliability and benchmark history →

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