Fugu vs Phi-4 Mini Flash Reasoning
Fugu (2026) and Phi-4 Mini Flash Reasoning (2025) are frontier-tier reasoning models from Sakana AI and Microsoft Research. Fugu 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. It focuses on practical selection signals rather than broad model-family marketing.
Fugu 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 | Fugu | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps |
| Decision fit | Coding, RAG, and Agents | Long context |
| Context window | 1m | 128k |
| Cheapest output | - | - |
| Provider routes | 1 tracked | 1 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Fugu has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Fugu uniquely exposes Vision, Multimodal, and Function calling in local model data.
- Local decision data tags Fugu for Coding, RAG, and Agents.
- 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.
Fugu
Unavailable
No complete token price in local provider data
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 Fugu and Phi-4 Mini Flash Reasoning; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Vision, Multimodal, and Function calling before moving production traffic.
- No overlapping tracked provider route is sourced for Phi-4 Mini Flash Reasoning and Fugu; plan for SDK, billing, or endpoint changes.
- Fugu adds Vision, Multimodal, and Function calling in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-06-22 | 2025-12-01 |
| Context window | 1m | 128k |
| Parameters | — | 3.8B |
| Architecture | Composition of Experts | Decoder Only |
| License | Proprietary | MITOSI-approved |
| Openness | Proprietary | Open source |
| Commercial use | Commercial use: conditional | Commercial use: permitted |
| Knowledge cutoff | - | 2025-02 |
Pricing and availability
| Pricing attribute | Fugu | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Input price | - | - |
| Output price | - | - |
| Providers |
Pricing not yet sourced for either model.
Capabilities
| Capability | Fugu | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | Yes |
| Function calling | Yes | No |
| Tool use | Yes | 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.
Deep dive
The capability footprint differs most on vision: Fugu, multimodal input: Fugu, function calling: Fugu, tool use: Fugu, and structured outputs: Fugu. Both models share reasoning mode, 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: Fugu has no token price sourced yet and Phi-4 Mini Flash Reasoning has no token price sourced yet. Provider availability is 1 tracked routes versus 1. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose Fugu when long-context analysis and larger context windows are central to the workload. Choose Phi-4 Mini Flash Reasoning 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. 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
Which has a larger context window, Fugu or Phi-4 Mini Flash Reasoning?
Fugu supports 1m tokens, while Phi-4 Mini Flash 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 Fugu or Phi-4 Mini Flash Reasoning open source?
Fugu is listed under Proprietary. Phi-4 Mini Flash Reasoning 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, Fugu or Phi-4 Mini Flash Reasoning?
Fugu 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. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, Fugu or Phi-4 Mini Flash Reasoning?
Fugu 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, Fugu or Phi-4 Mini Flash Reasoning?
Both Fugu and Phi-4 Mini Flash Reasoning expose reasoning mode. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Fugu and Phi-4 Mini Flash Reasoning?
Fugu is available on Sakana AI. Phi-4 Mini Flash Reasoning is available on NVIDIA NIM. Provider coverage can affect latency, region availability, compliance posture, and fallback options. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Continue comparing
Last reviewed: 2026-06-22. Data sourced from public model cards and provider documentation.