Gemini 3.1 Flash Lite Preview vs Phi-4 Mini Reasoning
Gemini 3.1 Flash Lite Preview (2026) and Phi-4 Mini Reasoning (2026) are frontier reasoning models from Google DeepMind and Microsoft Research. Gemini 3.1 Flash Lite Preview ships a 1M-token context window, while Phi-4 Mini Reasoning ships a 128K-token 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.
Gemini 3.1 Flash Lite Preview fits 8x more tokens; pick it for long-context work and Phi-4 Mini Reasoning for tighter calls.
Decision scorecard
Local evidence first| Signal | Gemini 3.1 Flash Lite Preview | Phi-4 Mini Reasoning |
|---|---|---|
| Best for | multimodal apps, tool-calling agents, and long-context analysis | reasoning-heavy apps |
| Decision fit | Coding, RAG, and Agents | Long context |
| Context window | 1M | 128K |
| Cheapest output | $1.50/1M tokens | - |
| Provider routes | 4 tracked | 0 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Gemini 3.1 Flash Lite Preview has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Gemini 3.1 Flash Lite Preview has broader tracked provider coverage for fallback and procurement flexibility.
- Gemini 3.1 Flash Lite Preview uniquely exposes Vision, Multimodal, and Function calling in local model data.
- Local decision data tags Gemini 3.1 Flash Lite Preview for Coding, RAG, and Agents.
- Phi-4 Mini Reasoning uniquely exposes Reasoning in local model data.
- Local decision data tags Phi-4 Mini 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 Flash Lite Preview
$575
Cheapest tracked route/tier: Google AI Studio
Phi-4 Mini 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 Flash Lite Preview and Phi-4 Mini Reasoning; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Vision, Multimodal, and Function calling before moving production traffic.
- Phi-4 Mini Reasoning adds Reasoning in local capability data.
- No overlapping tracked provider route is sourced for Phi-4 Mini Reasoning and Gemini 3.1 Flash Lite Preview; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Reasoning before moving production traffic.
- Gemini 3.1 Flash Lite Preview adds Vision, Multimodal, and Function calling in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-03-03 | 2026-05-16 |
| Context window | 1M | 128K |
| Parameters | — | 3.8B |
| Architecture | decoder only | - |
| License | Proprietary | Proprietary |
| Knowledge cutoff | 2025-01 | 2025-02 |
Pricing and availability
| Pricing attribute | Gemini 3.1 Flash Lite Preview | Phi-4 Mini Reasoning |
|---|---|---|
| Input price | $0.25/1M tokens | - |
| Output price | $1.50/1M tokens | - |
| Providers | - |
Capabilities
| Capability | Gemini 3.1 Flash Lite Preview | Phi-4 Mini Reasoning |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | No | Yes |
| Function calling | Yes | No |
| 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 rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on vision: Gemini 3.1 Flash Lite Preview, multimodal input: Gemini 3.1 Flash Lite Preview, reasoning mode: Phi-4 Mini Reasoning, function calling: Gemini 3.1 Flash Lite Preview, tool use: Gemini 3.1 Flash Lite Preview, structured outputs: Gemini 3.1 Flash Lite Preview, and code execution: Gemini 3.1 Flash Lite Preview. 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 3.1 Flash Lite Preview has $0.25/1M input tokens and Phi-4 Mini Reasoning 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 Gemini 3.1 Flash Lite Preview when coding workflow support, larger context windows, and broader provider choice are central to the workload. Choose Phi-4 Mini Reasoning when reasoning depth are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Gemini 3.1 Flash Lite Preview or Phi-4 Mini Reasoning?
Gemini 3.1 Flash Lite Preview supports 1M tokens, while Phi-4 Mini Reasoning supports 128K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is Gemini 3.1 Flash Lite Preview or Phi-4 Mini Reasoning open source?
Gemini 3.1 Flash Lite Preview is listed under Proprietary. Phi-4 Mini Reasoning is listed under Proprietary. 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 3.1 Flash Lite Preview or Phi-4 Mini Reasoning?
Gemini 3.1 Flash Lite Preview 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 3.1 Flash Lite Preview or Phi-4 Mini Reasoning?
Gemini 3.1 Flash Lite Preview 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 reasoning mode, Gemini 3.1 Flash Lite Preview or Phi-4 Mini Reasoning?
Phi-4 Mini Reasoning 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.
Where can I run Gemini 3.1 Flash Lite Preview and Phi-4 Mini Reasoning?
Gemini 3.1 Flash Lite Preview is available on Google AI Studio, GCP Vertex AI, OpenRouter, and Vercel AI Gateway. Phi-4 Mini Reasoning 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: 2026-05-22. Data sourced from public model cards and provider documentation.