LLM ReferenceLLM Reference

Claude Opus 4.5 vs Phi-4 Reasoning Vision 15B

Claude Opus 4.5 (2025) and Phi-4 Reasoning Vision 15B (2026) are frontier reasoning models from Anthropic and Microsoft Research. Claude Opus 4.5 ships a 200K-token context window, while Phi-4 Reasoning Vision 15B ships a not-yet-sourced context window. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing.

Phi-4 Reasoning Vision 15B is safer overall; choose Claude Opus 4.5 when coding workflow support matters.

Specs

Released2025-11-012026-03-12
Context window200K
Parameters15B
Architecturedecoder only-
LicenseProprietaryMicrosoft Research
Knowledge cutoff2025-12-

Pricing and availability

Claude Opus 4.5Phi-4 Reasoning Vision 15B
Input price$5/1M tokens-
Output price$25/1M tokens-
Providers-

Capabilities

Claude Opus 4.5Phi-4 Reasoning Vision 15B
Vision
Multimodal
Reasoning
Function calling
Tool use
Structured outputs
Code execution

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

The capability footprint differs most on vision: Claude Opus 4.5, reasoning mode: Claude Opus 4.5, function calling: Claude Opus 4.5, tool use: Claude Opus 4.5, structured outputs: Claude Opus 4.5, and code execution: Claude Opus 4.5. Both models share multimodal input, 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: Claude Opus 4.5 has $5/1M input tokens and Phi-4 Reasoning Vision 15B has no token price sourced yet. Provider availability is 6 tracked routes versus 0. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.

Choose Claude Opus 4.5 when coding workflow support and broader provider choice are central to the workload. Choose Phi-4 Reasoning Vision 15B when provider fit are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions.

FAQ

Is Claude Opus 4.5 or Phi-4 Reasoning Vision 15B open source?

Claude Opus 4.5 is listed under Proprietary. Phi-4 Reasoning Vision 15B is listed under Microsoft Research. 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, Claude Opus 4.5 or Phi-4 Reasoning Vision 15B?

Claude Opus 4.5 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, Claude Opus 4.5 or Phi-4 Reasoning Vision 15B?

Both Claude Opus 4.5 and Phi-4 Reasoning Vision 15B expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.

Which is better for reasoning mode, Claude Opus 4.5 or Phi-4 Reasoning Vision 15B?

Claude Opus 4.5 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.

Which is better for function calling, Claude Opus 4.5 or Phi-4 Reasoning Vision 15B?

Claude Opus 4.5 has the clearer documented function calling signal in this comparison. If function calling is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.

Where can I run Claude Opus 4.5 and Phi-4 Reasoning Vision 15B?

Claude Opus 4.5 is available on Microsoft Foundry, Anthropic, GCP Vertex AI, AWS Bedrock, and OpenRouter. 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.

Continue comparing

Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.