GPT-5.2 Codex vs Phi-4 Mini Reasoning
GPT-5.2 Codex (2025) and Phi-4 Mini Reasoning (2026) compare a coding-specialized model against a standalone API model. GPT-5.2 Codex ships a not-yet-sourced context window, while Phi-4 Mini Reasoning ships a 128k-token context window. This page treats the result as workflow and deployment fit, not a universal model winner.
Treat this as a product-type comparison: GPT-5.2 Codex is coding-specialized model, while Phi-4 Mini Reasoning is standalone API model. Choose based on workflow fit before reading any benchmark or price row as decisive.
Decision scorecard
Local evidence first| Signal | GPT-5.2 Codex | Phi-4 Mini Reasoning |
|---|---|---|
| Product type | Coding-specialized model | Standalone API model |
| Best for | custom coding agents, code generation, and tool loops | reasoning-heavy apps |
| Decision fit | Coding, Agents, and Vision | Long context |
| Context window | — | 128k |
| Cheapest output | $14/1M tokens | - |
| Provider routes | 1 tracked | 0 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- GPT-5.2 Codex has broader tracked provider coverage for fallback and procurement flexibility.
- GPT-5.2 Codex uniquely exposes Vision, Multimodal, and Function calling in local model data.
- Local decision data tags GPT-5.2 Codex for Coding, Agents, and Vision.
- Phi-4 Mini Reasoning has the larger context window for long prompts, retrieval packs, or transcript analysis.
- 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.
GPT-5.2 Codex
$4,900
Cheapest tracked route/tier: Vercel AI Gateway
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
- No overlapping tracked provider route is sourced for GPT-5.2 Codex 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.
- No overlapping tracked provider route is sourced for Phi-4 Mini Reasoning and GPT-5.2 Codex; plan for SDK, billing, or endpoint changes.
- GPT-5.2 Codex adds Vision, Multimodal, and Function calling in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-12-18 | 2026-05-16 |
| Context window | — | 128k |
| Parameters | — | 3.8B |
| Architecture | decoder only | - |
| License | Proprietary | MIT(OSI) |
| Openness | Proprietary | Open source |
| Commercial use | Commercial use with conditions | Commercial use allowed |
| Knowledge cutoff | 2025-08 | 2025-02 |
Pricing and availability
| Pricing attribute | GPT-5.2 Codex | Phi-4 Mini Reasoning |
|---|---|---|
| Input price | $1.75/1M tokens | - |
| Output price | $14/1M tokens | - |
| Providers | - |
Capabilities
| Capability | GPT-5.2 Codex | Phi-4 Mini Reasoning |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | Yes |
| Function calling | Yes | No |
| Tool use | Yes | No |
| Structured outputs | No | No |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on vision: GPT-5.2 Codex, multimodal input: GPT-5.2 Codex, function calling: GPT-5.2 Codex, tool use: GPT-5.2 Codex, and code execution: GPT-5.2 Codex. 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: GPT-5.2 Codex has $1.75/1M input tokens 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 GPT-5.2 Codex when coding workflow support 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. 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
Is GPT-5.2 Codex or Phi-4 Mini Reasoning open source?
GPT-5.2 Codex 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, GPT-5.2 Codex or Phi-4 Mini Reasoning?
GPT-5.2 Codex 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, GPT-5.2 Codex or Phi-4 Mini Reasoning?
GPT-5.2 Codex 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, GPT-5.2 Codex or Phi-4 Mini Reasoning?
Both GPT-5.2 Codex 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.
Which is better for function calling, GPT-5.2 Codex or Phi-4 Mini Reasoning?
GPT-5.2 Codex 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.
Where can I run GPT-5.2 Codex and Phi-4 Mini Reasoning?
GPT-5.2 Codex is available on Vercel AI Gateway. 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: 2026-05-22. Data sourced from public model cards and provider documentation.