Gemini 3.1 Pro Preview Custom Tools vs Phi-4 Mini Flash Reasoning
Gemini 3.1 Pro Preview Custom Tools (2026) and Phi-4 Mini Flash Reasoning (2025) are frontier reasoning models from Google DeepMind and Microsoft Research. Gemini 3.1 Pro Preview Custom Tools ships a 1m-token context window, while Phi-4 Mini Flash Reasoning ships a 128k-token context window. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Gemini 3.1 Pro Preview Custom Tools fits 8x more tokens; pick it for long-context work and Phi-4 Mini Flash Reasoning for tighter calls.
Decision scorecard
Local evidence first| Signal | Gemini 3.1 Pro Preview Custom Tools | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Best for | multimodal apps and long-context analysis | reasoning-heavy apps |
| Decision fit | RAG, Long context, and Vision | Long context |
| Context window | 1m | 128k |
| Cheapest output | $12/1M tokens | - |
| Provider routes | 1 tracked | 1 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Gemini 3.1 Pro Preview Custom Tools has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Gemini 3.1 Pro Preview Custom Tools uniquely exposes Vision, Multimodal, and Structured outputs in local model data.
- Local decision data tags Gemini 3.1 Pro Preview Custom Tools for RAG, Long context, and Vision.
- Phi-4 Mini Flash Reasoning uniquely exposes Reasoning in local model data.
- Local decision data tags Phi-4 Mini Flash Reasoning for Long context.
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 Custom Tools
$4,600
Cheapest tracked route/tier: OpenRouter
Phi-4 Mini Flash Reasoning
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 Custom Tools and Phi-4 Mini Flash Reasoning; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Vision, Multimodal, and Structured outputs before moving production traffic.
- Phi-4 Mini Flash Reasoning adds Reasoning in local capability data.
- No overlapping tracked provider route is sourced for Phi-4 Mini Flash Reasoning and Gemini 3.1 Pro Preview Custom Tools; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Reasoning before moving production traffic.
- Gemini 3.1 Pro Preview Custom Tools adds Vision, Multimodal, and Structured outputs in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-01-01 | 2025-12-01 |
| Context window | 1m | 128k |
| Parameters | — | 3.8B |
| Architecture | Decoder Only | 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 | 2025-02 |
Pricing and availability
| Pricing attribute | Gemini 3.1 Pro Preview Custom Tools | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Input price | $2/1M tokens | - |
| Output price | $12/1M tokens | - |
| Providers |
Capabilities
| Capability | Gemini 3.1 Pro Preview Custom Tools | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | No | Yes |
| JSON / Tool use | No | No |
| Structured outputs | Yes | No |
| Code execution | No | 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
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Popular comparisons for Phi-4 Mini Flash Reasoning
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- Phi-4 Mini Flash Reasoning vs Gemma 2 9B SahabatAI Instruct
- Phi-4 Mini Flash Reasoning vs ByteDance Doubao Seed 2.0 Pro
- Phi-4 Mini Flash Reasoning vs Llama 3 8B Instruct
- Phi-4 Mini Flash Reasoning vs Llama 3.2 1B Instruct
Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.