LLM Reference

Gemini 1.5 Pro vs Phi-4 Reasoning Vision 15B

Gemini 1.5 Pro (2024) and Phi-4 Reasoning Vision 15B (2026) are general-purpose language models from Google DeepMind and Microsoft Research. Gemini 1.5 Pro ships a 2m-token context window, while Phi-4 Reasoning Vision 15B ships a not-yet-sourced context window. On Massive Multi-discipline Multimodal Understanding, Gemini 1.5 Pro leads by 11.5 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 Reasoning Vision 15B is safer overall; choose Gemini 1.5 Pro when provider fit matters.

Decision scorecard

Local evidence first
SignalGemini 1.5 ProPhi-4 Reasoning Vision 15B
Best forlong-context analysis and provider-routed productionmultimodal apps
Decision fitRAG, Long context, and VisionVision
Context window2m
Cheapest output$5/1M tokens-
Provider routes2 tracked0 tracked
Shared benchmarksMassive Multi-discipline Multimodal Understanding leader1 shared

Decision tradeoffs

Choose Gemini 1.5 Pro when...
  • Gemini 1.5 Pro holds a shared-benchmark lead on Massive Multi-discipline Multimodal Understanding, ahead by 11.5 points.
  • Gemini 1.5 Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Gemini 1.5 Pro has broader tracked provider coverage for fallback and procurement flexibility.
  • Gemini 1.5 Pro uniquely exposes Structured outputs in local model data.
  • Local decision data tags Gemini 1.5 Pro for RAG, Long context, and Vision.
Choose Phi-4 Reasoning Vision 15B when...
  • Phi-4 Reasoning Vision 15B uniquely exposes Vision and Multimodal in local model data.
  • 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.

Gemini 1.5 Pro

$2,250

Cheapest tracked route/tier: GCP Vertex AI

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

Gemini 1.5 Pro -> Phi-4 Reasoning Vision 15B
  • No overlapping tracked provider route is sourced for Gemini 1.5 Pro and Phi-4 Reasoning Vision 15B; plan for SDK, billing, or endpoint changes.
  • Check replacement coverage for Structured outputs before moving production traffic.
  • Phi-4 Reasoning Vision 15B adds Vision and Multimodal in local capability data.
Phi-4 Reasoning Vision 15B -> Gemini 1.5 Pro
  • No overlapping tracked provider route is sourced for Phi-4 Reasoning Vision 15B and Gemini 1.5 Pro; plan for SDK, billing, or endpoint changes.
  • Check replacement coverage for Vision and Multimodal before moving production traffic.
  • Gemini 1.5 Pro adds Structured outputs in local capability data.

Specs

Specification
Released2024-02-152026-03-12
Context window2m
Parameters15B
ArchitectureDecoder Only-
LicenseProprietaryMITOSI-approved
OpennessProprietaryOpen source
Commercial useCommercial use: conditionalCommercial use: permitted
Knowledge cutoff2023-112025-03

Pricing and availability

Pricing attributeGemini 1.5 ProPhi-4 Reasoning Vision 15B
Input price$1.25/1M tokens-
Output price$5/1M tokens-
Providers-

Capabilities

CapabilityGemini 1.5 ProPhi-4 Reasoning Vision 15B
VisionNoYes
MultimodalNoYes
ReasoningNoNo
Function callingNoNo
Tool useNoNo
Structured outputsYesNo
Code executionNoNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkGemini 1.5 ProPhi-4 Reasoning Vision 15B
Massive Multi-discipline Multimodal Understanding65.854.3

Deep dive

On shared benchmark coverage, Massive Multi-discipline Multimodal Understanding has Gemini 1.5 Pro at 65.8 and Phi-4 Reasoning Vision 15B at 54.3, with Gemini 1.5 Pro ahead by 11.5 points. The largest visible gap is 11.5 points on Massive Multi-discipline Multimodal Understanding, 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: Phi-4 Reasoning Vision 15B, multimodal input: Phi-4 Reasoning Vision 15B, and structured outputs: Gemini 1.5 Pro. 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: Gemini 1.5 Pro has $1.25/1M input tokens and Phi-4 Reasoning Vision 15B has no token price sourced yet. Provider availability is 2 tracked routes versus 0. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.

Choose Gemini 1.5 Pro when provider fit and broader provider choice are central to the workload. Choose Phi-4 Reasoning Vision 15B when vision-heavy evaluation are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.

FAQ

Is Gemini 1.5 Pro or Phi-4 Reasoning Vision 15B open source?

Gemini 1.5 Pro is listed under Proprietary. Phi-4 Reasoning Vision 15B 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, Gemini 1.5 Pro or Phi-4 Reasoning Vision 15B?

Phi-4 Reasoning Vision 15B 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, Gemini 1.5 Pro or Phi-4 Reasoning Vision 15B?

Phi-4 Reasoning Vision 15B 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 structured outputs, Gemini 1.5 Pro or Phi-4 Reasoning Vision 15B?

Gemini 1.5 Pro has the clearer documented structured outputs signal in this comparison. If structured outputs is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.

Where can I run Gemini 1.5 Pro and Phi-4 Reasoning Vision 15B?

Gemini 1.5 Pro is available on GCP Vertex AI and Google 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.

When should I pick Gemini 1.5 Pro over Phi-4 Reasoning Vision 15B?

Phi-4 Reasoning Vision 15B is safer overall; choose Gemini 1.5 Pro when provider fit matters. If your workload also depends on provider fit, start with Gemini 1.5 Pro; if it depends on vision-heavy evaluation, run the same evaluation with Phi-4 Reasoning Vision 15B.

Continue comparing

Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.