LLM Reference

Fugu vs Phi-4 Mini Reasoning

Fugu (2026) and Phi-4 Mini Reasoning (2026) are frontier-tier reasoning models from Sakana AI and Microsoft Research. Fugu ships a 1m-token context window, while Phi-4 Mini Reasoning ships a 128k-token context window. On Google-Proof Q&A, Fugu leads by 43.5 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.

Fugu fits 8x more tokens; pick it for long-context work and Phi-4 Mini Reasoning for tighter calls.

Decision scorecard

Local evidence first
SignalFuguPhi-4 Mini Reasoning
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsreasoning-heavy apps
Decision fitCoding, RAG, and AgentsLong context
Context window1m128k
Cheapest output--
Provider routes1 tracked0 tracked
Shared benchmarksGoogle-Proof Q&A leader1 shared

Decision tradeoffs

Choose Fugu when...
  • Fugu holds a shared-benchmark lead on Google-Proof Q&A, ahead by 43.5 points.
  • Fugu has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Fugu has broader tracked provider coverage for fallback and procurement flexibility.
  • Fugu uniquely exposes Vision, Multimodal, and Function calling in local model data.
  • Local decision data tags Fugu for Coding, RAG, and Agents.
Choose Phi-4 Mini Reasoning when...
  • 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.

Fugu

Unavailable

No complete token price in local provider data

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

Fugu -> Phi-4 Mini Reasoning
  • No overlapping tracked provider route is sourced for Fugu 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 -> Fugu
  • No overlapping tracked provider route is sourced for Phi-4 Mini Reasoning and Fugu; plan for SDK, billing, or endpoint changes.
  • Fugu adds Vision, Multimodal, and Function calling in local capability data.

Specs

Specification
Released2026-06-222026-05-16
Context window1m128k
Parameters3.8B
ArchitectureComposition of Experts-
LicenseProprietaryMITOSI-approved
OpennessProprietaryOpen source
Commercial useCommercial use: conditionalCommercial use: permitted
Knowledge cutoff-2025-02

Pricing and availability

Pricing attributeFuguPhi-4 Mini Reasoning
Input price--
Output price--
Providers-

Pricing not yet sourced for either model.

Capabilities

CapabilityFuguPhi-4 Mini Reasoning
VisionYesNo
MultimodalYesNo
ReasoningYesYes
Function callingYesNo
Tool useYesNo
Structured outputsYesNo
Code executionNoNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkFuguPhi-4 Mini Reasoning
Google-Proof Q&A95.552.0

Deep dive

On shared benchmark coverage, Google-Proof Q&A has Fugu at 95.5 and Phi-4 Mini Reasoning at 52, with Fugu ahead by 43.5 points. The largest visible gap is 43.5 points on Google-Proof Q&A, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.

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 Reasoning has no token price sourced yet. Provider availability is 1 tracked routes versus 0. 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, larger context windows, and broader provider choice are central to the workload. Choose Phi-4 Mini 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.

FAQ

Which has a larger context window, Fugu or Phi-4 Mini Reasoning?

Fugu 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 Fugu or Phi-4 Mini Reasoning open source?

Fugu is listed under Proprietary. Phi-4 Mini 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 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 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 Reasoning?

Both Fugu and Phi-4 Mini Reasoning expose reasoning mode. 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.

Where can I run Fugu and Phi-4 Mini Reasoning?

Fugu is available on Sakana AI. 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: 2026-06-22. Data sourced from public model cards and provider documentation.