Gemini 3.1 Pro Preview vs Phi-4 Reasoning Vision 15B
Gemini 3.1 Pro Preview (2026) and Phi-4 Reasoning Vision 15B (2026) are general-purpose language models from Google DeepMind and Microsoft Research. Gemini 3.1 Pro Preview ships a 1m-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.
Phi-4 Reasoning Vision 15B is safer overall; choose Gemini 3.1 Pro Preview when coding workflow support matters.
Decision scorecard
Local evidence first| Signal | Gemini 3.1 Pro Preview | Phi-4 Reasoning Vision 15B |
|---|---|---|
| Best for | multimodal apps, tool-calling agents, and long-context analysis | multimodal apps |
| Decision fit | Coding, RAG, and Agents | Vision |
| Context window | 1m | — |
| Cheapest output | $12/1M tokens | - |
| Provider routes | 5 tracked | 0 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Gemini 3.1 Pro Preview has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Gemini 3.1 Pro Preview has broader tracked provider coverage for fallback and route flexibility.
- Gemini 3.1 Pro Preview uniquely exposes JSON / Tool use, Structured outputs, and Code execution in local model data.
- Local decision data tags Gemini 3.1 Pro Preview for Coding, RAG, and Agents.
- 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 3.1 Pro Preview
$4,600
Cheapest tracked route/tier: Google AI Studio
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 Gemini 3.1 Pro Preview and Phi-4 Reasoning Vision 15B; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for JSON / Tool use, Structured outputs, and Code execution before moving production traffic.
- No overlapping tracked provider route is sourced for Phi-4 Reasoning Vision 15B and Gemini 3.1 Pro Preview; plan for SDK, billing, or endpoint changes.
- Gemini 3.1 Pro Preview adds JSON / Tool use, Structured outputs, and Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-02-19 | 2026-03-12 |
| Context window | 1m | — |
| Parameters | — | 15B |
| Architecture | Decoder Only | - |
| License | Proprietary | MITOSI-approved |
| Openness | Proprietary | Open source |
| Weights | Not released | Unknown |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: permitted |
| Knowledge cutoff | 2025-01 | 2025-03 |
Pricing and availability
| Pricing attribute | Gemini 3.1 Pro Preview | Phi-4 Reasoning Vision 15B |
|---|---|---|
| Input price |
| - |
| Output price |
| - |
| Providers | - |
Capabilities
| Capability | Gemini 3.1 Pro Preview | Phi-4 Reasoning Vision 15B |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | No | No |
| JSON / Tool use | Yes | 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 scores are currently available for this pair.
Continue comparing
Popular comparisons for Gemini 3.1 Pro Preview
Popular comparisons for Phi-4 Reasoning Vision 15B
Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.