Grok Code Fast 1 vs Phi-4 Mini Flash Reasoning
Grok Code Fast 1 (2025) and Phi-4 Mini Flash Reasoning (2025) are agentic coding models from xAI and Microsoft Research. Grok Code Fast 1 ships a 262K-token context window, while Phi-4 Mini Flash 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.
Phi-4 Mini Flash Reasoning is safer overall; choose Grok Code Fast 1 when coding workflow support matters.
Specs
| Released | 2025-08-27 | 2025-12-01 |
| Context window | 262K | 128K |
| Parameters | 314B | — |
| Architecture | mixture of experts | decoder only |
| License | Proprietary | 1 |
| Knowledge cutoff | - | - |
Pricing and availability
| Grok Code Fast 1 | Phi-4 Mini Flash Reasoning | |
|---|---|---|
| Input price | $0.2/1M tokens | - |
| Output price | $1.5/1M tokens | - |
| Providers |
Capabilities
| Grok Code Fast 1 | Phi-4 Mini Flash Reasoning | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
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, function calling: Grok Code Fast 1, tool use: Grok Code Fast 1, and structured outputs: Grok Code Fast 1. 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: Grok Code Fast 1 has $0.2/1M input tokens 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 Grok Code Fast 1 when coding workflow support and larger context windows are central to the workload. Choose Phi-4 Mini Flash 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. 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.
FAQ
Which has a larger context window, Grok Code Fast 1 or Phi-4 Mini Flash Reasoning?
Grok Code Fast 1 supports 262K 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 Grok Code Fast 1 or Phi-4 Mini Flash Reasoning open source?
Grok Code Fast 1 is listed under Proprietary. Phi-4 Mini Flash Reasoning is listed under 1. 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, Grok Code Fast 1 or Phi-4 Mini Flash Reasoning?
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.
Which is better for function calling, Grok Code Fast 1 or Phi-4 Mini Flash Reasoning?
Grok Code Fast 1 has the clearer documented function calling signal in this comparison. If function calling is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for tool use, Grok Code Fast 1 or Phi-4 Mini Flash Reasoning?
Grok Code Fast 1 has the clearer documented tool use signal in this comparison. If tool use is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Grok Code Fast 1 and Phi-4 Mini Flash Reasoning?
Grok Code Fast 1 is available on OpenRouter. 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.
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Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.