o3 Deep Research vs Phi-4 Mini Flash Reasoning
o3 Deep Research (2025) and Phi-4 Mini Flash Reasoning (2025) are frontier-tier reasoning models from OpenAI and Microsoft Research. o3 Deep Research ships a 200k-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.
Phi-4 Mini Flash Reasoning is safer overall; choose o3 Deep Research when long-context analysis matters.
Decision scorecard
Local evidence first| Signal | o3 Deep Research | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps |
| Decision fit | RAG, Agents, and Long context | Long context |
| Context window | 200k | 128k |
| Cheapest output | $40/1M tokens | - |
| Provider routes | 2 tracked | 1 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- o3 Deep Research has the larger context window for long prompts, retrieval packs, or transcript analysis.
- o3 Deep Research has broader tracked provider coverage for fallback and route flexibility.
- o3 Deep Research uniquely exposes Vision, Multimodal, and JSON / Tool use in local model data.
- Local decision data tags o3 Deep Research for RAG, Agents, and Long context.
- 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.
o3 Deep Research
$18,000
Cheapest tracked route/tier: Vercel AI Gateway
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 o3 Deep Research and Phi-4 Mini Flash Reasoning; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Vision, Multimodal, and JSON / Tool use before moving production traffic.
- No overlapping tracked provider route is sourced for Phi-4 Mini Flash Reasoning and o3 Deep Research; plan for SDK, billing, or endpoint changes.
- o3 Deep Research adds Vision, Multimodal, and JSON / Tool use in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-10-10 | 2025-12-01 |
| Context window | 200k | 128k |
| Parameters | — | 3.8B |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | MITOSI-approved |
| Openness | Proprietary | Open source |
| Weights | Not released | Unknown |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: permitted |
| Knowledge cutoff | 2024-06 | 2025-02 |
Pricing and availability
| Pricing attribute | o3 Deep Research | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Input price | $10/1M tokens | - |
| Output price | $40/1M tokens | - |
| Providers |
Capabilities
| Capability | o3 Deep Research | Phi-4 Mini Flash Reasoning |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | Yes |
| JSON / 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.
Continue comparing
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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.