gpt-oss-120b vs Phi-4 Mini Reasoning
gpt-oss-120b (2025) and Phi-4 Mini Reasoning (2026) are frontier reasoning models from OpenAI and Microsoft Research. gpt-oss-120b ships a 131k-token context window, while Phi-4 Mini Reasoning ships a 128k-token context window. On Google-Proof Q&A, gpt-oss-120b leads by 26.2 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Phi-4 Mini Reasoning is safer overall; choose gpt-oss-120b when long-context analysis matters.
Decision scorecard
Local evidence first| Signal | gpt-oss-120b | Phi-4 Mini Reasoning |
|---|---|---|
| Best for | tool-calling agents and provider-routed production | reasoning-heavy apps |
| Decision fit | RAG, Agents, and Long context | Long context |
| Context window | 131k | 128k |
| Cheapest output | $0.18/1M tokens | - |
| Provider routes | 10 tracked | 0 tracked |
| Shared benchmarks | Google-Proof Q&A leader | 1 rows |
Decision tradeoffs
- gpt-oss-120b leads the largest shared benchmark signal on Google-Proof Q&A by 26.2 points.
- gpt-oss-120b has the larger context window for long prompts, retrieval packs, or transcript analysis.
- gpt-oss-120b has broader tracked provider coverage for fallback and procurement flexibility.
- gpt-oss-120b uniquely exposes Function calling, Tool use, and Structured outputs in local model data.
- Local decision data tags gpt-oss-120b for RAG, Agents, and Long context.
- Phi-4 Mini Reasoning uniquely exposes Reasoning in local model data.
- 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-oss-120b
$76.20
Cheapest tracked route/tier: OpenRouter
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-oss-120b and Phi-4 Mini Reasoning; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Function calling, Tool use, and Structured outputs before moving production traffic.
- Phi-4 Mini Reasoning adds Reasoning in local capability data.
- No overlapping tracked provider route is sourced for Phi-4 Mini Reasoning and gpt-oss-120b; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Reasoning before moving production traffic.
- gpt-oss-120b adds Function calling, Tool use, and Structured outputs in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-08-05 | 2026-05-16 |
| Context window | 131k | 128k |
| Parameters | 120B | 3.8B |
| Architecture | decoder only | - |
| License | Open Weights | Proprietary |
| Knowledge cutoff | 2025-08 | 2025-02 |
Pricing and availability
| Pricing attribute | gpt-oss-120b | Phi-4 Mini Reasoning |
|---|---|---|
| Input price | $0.04/1M tokens | - |
| Output price | $0.18/1M tokens | - |
| Providers | - |
Capabilities
| Capability | gpt-oss-120b | Phi-4 Mini Reasoning |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | No | Yes |
| Function calling | Yes | No |
| 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
| Benchmark | gpt-oss-120b | Phi-4 Mini Reasoning |
|---|---|---|
| Google-Proof Q&A | 78.2 | 52.0 |
Deep dive
On shared benchmark coverage, Google-Proof Q&A has gpt-oss-120b at 78.2 and Phi-4 Mini Reasoning at 52, with gpt-oss-120b ahead by 26.2 points. The largest visible gap is 26.2 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 reasoning mode: Phi-4 Mini Reasoning, function calling: gpt-oss-120b, tool use: gpt-oss-120b, and structured outputs: gpt-oss-120b. 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: gpt-oss-120b has $0.04/1M input tokens and Phi-4 Mini Reasoning has no token price sourced yet. Provider availability is 10 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-oss-120b when long-context analysis, larger context windows, and broader provider choice are central to the workload. Choose Phi-4 Mini 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.
FAQ
Which has a larger context window, gpt-oss-120b or Phi-4 Mini Reasoning?
gpt-oss-120b supports 131k 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 gpt-oss-120b or Phi-4 Mini Reasoning open source?
gpt-oss-120b is listed under Open Weights. Phi-4 Mini Reasoning is listed under Proprietary. 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, gpt-oss-120b or Phi-4 Mini Reasoning?
Phi-4 Mini 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, gpt-oss-120b or Phi-4 Mini Reasoning?
gpt-oss-120b 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, gpt-oss-120b or Phi-4 Mini Reasoning?
gpt-oss-120b 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 gpt-oss-120b and Phi-4 Mini Reasoning?
gpt-oss-120b is available on Cloudflare Workers AI, OpenRouter, Together AI, Fireworks AI, and GCP Vertex 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: 2026-05-22. Data sourced from public model cards and provider documentation.