LLM Reference

GPT-5.4 Pro vs Phi-4 Reasoning Vision 15B

GPT-5.4 Pro (2026) and Phi-4 Reasoning Vision 15B (2026) are frontier reasoning models from OpenAI and Microsoft Research. GPT-5.4 Pro ships a 1.05m-token context window, while Phi-4 Reasoning Vision 15B ships a not-yet-sourced 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.

Phi-4 Reasoning Vision 15B is safer overall; choose GPT-5.4 Pro when coding workflow support matters.

Decision scorecard

Local evidence first
SignalGPT-5.4 ProPhi-4 Reasoning Vision 15B
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsmultimodal apps
Decision fitCoding, RAG, and AgentsVision
Context window1.05m—
Cheapest output$180/1M tokens-
Provider routes3 tracked0 tracked
Shared benchmarks0 shared0 shared

Decision tradeoffs

Choose GPT-5.4 Pro when...
  • GPT-5.4 Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • GPT-5.4 Pro has broader tracked provider coverage for fallback and route flexibility.
  • GPT-5.4 Pro uniquely exposes Reasoning, JSON / Tool use, and Structured outputs in local model data.
  • Local decision data tags GPT-5.4 Pro for Coding, RAG, and Agents.
Choose Phi-4 Reasoning Vision 15B when...
  • Local decision data tags Phi-4 Reasoning Vision 15B for Vision.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output route or tier on this page.

GPT-5.4 Pro

$69,000

Cheapest tracked route/tier: OpenRouter

Phi-4 Reasoning Vision 15B

Unavailable

No complete token price in local provider data

Cost delta unavailable until both models have sourced input and output token prices.

Switch friction

GPT-5.4 Pro -> Phi-4 Reasoning Vision 15B
  • No overlapping tracked provider route is sourced for GPT-5.4 Pro and Phi-4 Reasoning Vision 15B; plan for SDK, billing, or endpoint changes.
  • Check replacement coverage for Reasoning, JSON / Tool use, and Structured outputs before moving production traffic.
Phi-4 Reasoning Vision 15B -> GPT-5.4 Pro
  • No overlapping tracked provider route is sourced for Phi-4 Reasoning Vision 15B and GPT-5.4 Pro; plan for SDK, billing, or endpoint changes.
  • GPT-5.4 Pro adds Reasoning, JSON / Tool use, and Structured outputs in local capability data.

Specs

Specification
Released2026-03-012026-03-12
Context window1.05m—
Parameters—15B
ArchitectureDecoder Only-
LicenseProprietaryMITOSI-approved
OpennessProprietaryOpen source
WeightsNot releasedUnknown
CodeUnknownUnknown
Commercial useCommercial use: conditionalCommercial use: permitted
Knowledge cutoff2025-082025-03

Pricing and availability

Pricing attributeGPT-5.4 ProPhi-4 Reasoning Vision 15B
Input price
0-272,000t
$30/1M tokens
272,000t+
$60/1M tokens
-
Output price
0-272,000t
$180/1M tokens
272,000t+
$270/1M tokens
-
Providers-

Capabilities

CapabilityGPT-5.4 ProPhi-4 Reasoning Vision 15B
VisionYesYes
MultimodalYesYes
ReasoningYesNo
JSON / Tool useYesNo
Structured outputsYesNo
Code executionYesNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

No shared benchmark scores are currently available for this pair.

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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.