Model Comparison

GPT OSS 20B vs Phi 4 Mini ReasoningWhich is better in 2026?

GPT OSS 20B significantly outperforms across most benchmarks.

Verdict: GPT OSS 20B vs Phi 4 Mini Reasoning — which is better?

GPT OSS 20B (by OpenAI) and Phi 4 Mini Reasoning (by Microsoft) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

GPT OSS 20B outperforms in 1 benchmarks (GPQA), while Phi 4 Mini Reasoning is better at 0 benchmarks. GPT OSS 20B significantly outperforms across most benchmarks.

Choose GPT OSS 20B if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • you want the most recent training data — it shipped Aug 2025

Choose Phi 4 Mini Reasoning if…

  • you are already invested in the Microsoft ecosystem
Want to compare interactively?Try the playground

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

GPT OSS 20B outperforms in 1 benchmarks (GPQA), while Phi 4 Mini Reasoning is better at 0 benchmarks.

GPT OSS 20B significantly outperforms across most benchmarks.

Fri Jun 12 2026 • llm-stats.com

Arena Performance

Human preference votes

Model Size

Parameter count comparison

17.1B diff

GPT OSS 20B has 17.1B more parameters than Phi 4 Mini Reasoning, making it 450.0% larger.

OpenAI
GPT OSS 20B
20.9Bparameters
Microsoft
Phi 4 Mini Reasoning
3.8Bparameters
20.9B
GPT OSS 20B
3.8B
Phi 4 Mini Reasoning

Context Window

Maximum input and output token capacity

Only GPT OSS 20B specifies input context (131,072 tokens). Only GPT OSS 20B specifies output context (32,768 tokens).

OpenAI
GPT OSS 20B
Input131,072 tokens
Output32,768 tokens
Microsoft
Phi 4 Mini Reasoning
Input- tokens
Output- tokens
Fri Jun 12 2026 • llm-stats.com

License

Usage and distribution terms

GPT OSS 20B is licensed under Apache 2.0, while Phi 4 Mini Reasoning uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

GPT OSS 20B

Apache 2.0

Open weights

Phi 4 Mini Reasoning

MIT

Open weights

Release Timeline

When each model was launched

GPT OSS 20B was released on 2025-08-05, while Phi 4 Mini Reasoning was released on 2025-04-30.

GPT OSS 20B is 3 months newer than Phi 4 Mini Reasoning.

GPT OSS 20B

Aug 5, 2025

10 months ago

3mo newer
Phi 4 Mini Reasoning

Apr 30, 2025

1.1 years ago

Knowledge Cutoff

When training data ends

Phi 4 Mini Reasoning has a documented knowledge cutoff of 2025-02-01, while GPT OSS 20B's cutoff date is not specified.

We can confirm Phi 4 Mini Reasoning's training data extends to 2025-02-01, but cannot make a direct comparison without GPT OSS 20B's cutoff date.

GPT OSS 20B

—

Phi 4 Mini Reasoning

Feb 2025

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI
Larger context window (131,072 tokens)
Higher GPQA score (71.5% vs 52.0%)
Microsoft

No standout differentiators in the data we have for this pair.

Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT OSS 20B
Microsoft
Phi 4 Mini Reasoning

FAQ

Common questions about GPT OSS 20B vs Phi 4 Mini Reasoning.

Which is better, GPT OSS 20B or Phi 4 Mini Reasoning?

GPT OSS 20B significantly outperforms across most benchmarks. GPT OSS 20B is made by OpenAI and Phi 4 Mini Reasoning is made by Microsoft. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does GPT OSS 20B compare to Phi 4 Mini Reasoning in benchmarks?

GPT OSS 20B scores MMLU: 85.3%, CodeForces: 74.3%, GPQA: 71.5%, TAU-bench Retail: 54.8%, HealthBench: 42.5%. Phi 4 Mini Reasoning scores MATH-500: 94.6%, AIME: 57.5%, GPQA: 52.0%.

What are the context window sizes for GPT OSS 20B and Phi 4 Mini Reasoning?

GPT OSS 20B supports 131K tokens and Phi 4 Mini Reasoning supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT OSS 20B and Phi 4 Mini Reasoning?

Key differences include licensing (Apache 2.0 vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT OSS 20B and Phi 4 Mini Reasoning?

GPT OSS 20B is developed by OpenAI and Phi 4 Mini Reasoning is developed by Microsoft.

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