Phi-4 Mini Flash Reasoning vs Prompt Guard 86M
Phi-4 Mini Flash Reasoning (2025) and Prompt Guard 86M (2024) are frontier reasoning models from Microsoft Research and AI at Meta. Phi-4 Mini Flash Reasoning ships a 128K-token context window, while Prompt Guard 86M ships a 512-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.
Phi-4 Mini Flash Reasoning fits 250x more tokens; pick it for long-context work and Prompt Guard 86M for tighter calls.
Decision scorecard
Local evidence first| Signal | Phi-4 Mini Flash Reasoning | Prompt Guard 86M |
|---|---|---|
| Decision fit | Long context | General |
| Context window | 128K | 512 |
| Cheapest output | - | $0.05/1M tokens |
| Provider routes | 1 tracked | 1 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Phi-4 Mini Flash Reasoning has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Phi-4 Mini Flash Reasoning uniquely exposes Reasoning in local model data.
- Local decision data tags Phi-4 Mini Flash Reasoning for Long context.
- Use Prompt Guard 86M when your own prompt tests beat the comparison signals; the local data does not show a decisive standalone advantage yet.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output prices on this page.
Phi-4 Mini Flash Reasoning
Unavailable
No complete token price in local provider data
Prompt Guard 86M
$52.50
Cheapest tracked route: Microsoft Foundry
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- No overlapping tracked provider route is sourced for Phi-4 Mini Flash Reasoning and Prompt Guard 86M; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Reasoning before moving production traffic.
- No overlapping tracked provider route is sourced for Prompt Guard 86M and Phi-4 Mini Flash Reasoning; plan for SDK, billing, or endpoint changes.
- Phi-4 Mini Flash Reasoning adds Reasoning in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-12-01 | 2024-07-23 |
| Context window | 128K | 512 |
| Parameters | — | 279M |
| Architecture | decoder only | decoder only |
| License | 1 | Unknown |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Phi-4 Mini Flash Reasoning | Prompt Guard 86M |
|---|---|---|
| Input price | - | $0.05/1M tokens |
| Output price | - | $0.05/1M tokens |
| Providers |
Capabilities
| Capability | Phi-4 Mini Flash Reasoning | Prompt Guard 86M |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | Yes | No |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | No | No |
| Code execution | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on reasoning mode: Phi-4 Mini Flash Reasoning. 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: Phi-4 Mini Flash Reasoning has no token price sourced yet and Prompt Guard 86M has $0.05/1M input tokens. 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 Phi-4 Mini Flash Reasoning when reasoning depth and larger context windows are central to the workload. Choose Prompt Guard 86M 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, Phi-4 Mini Flash Reasoning or Prompt Guard 86M?
Phi-4 Mini Flash Reasoning supports 128K tokens, while Prompt Guard 86M supports 512 tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is Phi-4 Mini Flash Reasoning or Prompt Guard 86M open source?
Phi-4 Mini Flash Reasoning is listed under 1. Prompt Guard 86M is listed under Unknown. 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 reasoning mode, Phi-4 Mini Flash Reasoning or Prompt Guard 86M?
Phi-4 Mini Flash 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 Phi-4 Mini Flash Reasoning and Prompt Guard 86M?
Phi-4 Mini Flash Reasoning is available on NVIDIA NIM. Prompt Guard 86M is available on Microsoft Foundry. 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.
When should I pick Phi-4 Mini Flash Reasoning over Prompt Guard 86M?
Phi-4 Mini Flash Reasoning fits 250x more tokens; pick it for long-context work and Prompt Guard 86M for tighter calls. If your workload also depends on reasoning depth, start with Phi-4 Mini Flash Reasoning; if it depends on provider fit, run the same evaluation with Prompt Guard 86M.
Continue comparing
Last reviewed: 2026-05-16. Data sourced from public model cards and provider documentation.