GPT-4 vs Phi-4 Reasoning Vision 15B
GPT-4 (2023) and Phi-4 Reasoning Vision 15B (2026) are compact production models from OpenAI and Microsoft Research. GPT-4 ships a 8k-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-4 when coding workflow support matters.
Decision scorecard
Local evidence first| Signal | GPT-4 | Phi-4 Reasoning Vision 15B |
|---|---|---|
| Best for | multimodal apps, tool-calling agents, and provider-routed production | multimodal apps |
| Decision fit | Coding, Agents, and Vision | Vision |
| Context window | 8k | — |
| Cheapest output | $60/1M tokens | - |
| Provider routes | 4 tracked | 0 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- GPT-4 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-4 has broader tracked provider coverage for fallback and procurement flexibility.
- GPT-4 uniquely exposes Function calling, Structured outputs, and Code execution in local model data.
- Local decision data tags GPT-4 for Coding, Agents, and Vision.
- 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-4
$39,000
Cheapest tracked route/tier: OpenAI API
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
- No overlapping tracked provider route is sourced for GPT-4 and Phi-4 Reasoning Vision 15B; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Function calling, Structured outputs, and Code execution before moving production traffic.
- No overlapping tracked provider route is sourced for Phi-4 Reasoning Vision 15B and GPT-4; plan for SDK, billing, or endpoint changes.
- GPT-4 adds Function calling, Structured outputs, and Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2023-03-14 | 2026-03-12 |
| Context window | 8k | — |
| Parameters | 1.76T (8x222B MoE)* | 15B |
| Architecture | mixture of experts | - |
| License | Proprietary | MIT(OSI) |
| Openness | Proprietary | Open source |
| Commercial use | Commercial use with conditions | Commercial use allowed |
| Knowledge cutoff | 2021-09 | 2025-03 |
Pricing and availability
| Pricing attribute | GPT-4 | Phi-4 Reasoning Vision 15B |
|---|---|---|
| Input price | $30/1M tokens | - |
| Output price | $60/1M tokens | - |
| Providers | - |
Capabilities
| Capability | GPT-4 | Phi-4 Reasoning Vision 15B |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | No | No |
| Function calling | Yes | No |
| Tool use | No | No |
| Structured outputs | Yes | No |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on function calling: GPT-4, structured outputs: GPT-4, and code execution: GPT-4. Both models share vision and 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: GPT-4 has $30/1M input tokens and Phi-4 Reasoning Vision 15B has no token price sourced yet. Provider availability is 4 tracked routes versus 0. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose GPT-4 when coding workflow support 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. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency. For teams standardizing a stack, that distinction is often the difference between a benchmark win and a reliable deployment.
FAQ
Is GPT-4 or Phi-4 Reasoning Vision 15B open source?
GPT-4 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, GPT-4 or Phi-4 Reasoning Vision 15B?
Both GPT-4 and Phi-4 Reasoning Vision 15B expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, GPT-4 or Phi-4 Reasoning Vision 15B?
Both GPT-4 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 function calling, GPT-4 or Phi-4 Reasoning Vision 15B?
GPT-4 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.
Which is better for structured outputs, GPT-4 or Phi-4 Reasoning Vision 15B?
GPT-4 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 GPT-4 and Phi-4 Reasoning Vision 15B?
GPT-4 is available on OpenAI API, Azure OpenAI, Salesforce Einstein Generative AI, 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: 2026-06-04. Data sourced from public model cards and provider documentation.