Model Comparison

Grok-1.5 vs Phi 4 ReasoningWhich is better in 2026?

Phi 4 Reasoning significantly outperforms across most benchmarks.

Verdict: Grok-1.5 vs Phi 4 Reasoning — which is better?

Grok-1.5 (by xAI) and Phi 4 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.

Grok-1.5 outperforms in 0 benchmarks, while Phi 4 Reasoning is better at 2 benchmarks (GPQA, MMLU-Pro). Phi 4 Reasoning significantly outperforms across most benchmarks.

Choose Grok-1.5 if…

  • you are already invested in the xAI ecosystem

Choose Phi 4 Reasoning if…

  • you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
  • you want the most recent training data — it shipped Apr 2025
  • you need open weights you can self-host or fine-tune
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Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Grok-1.5 outperforms in 0 benchmarks, while Phi 4 Reasoning is better at 2 benchmarks (GPQA, MMLU-Pro).

Phi 4 Reasoning significantly outperforms across most benchmarks.

Sat Jun 13 2026 • llm-stats.com

Arena Performance

Human preference votes

License

Usage and distribution terms

Grok-1.5 is licensed under a proprietary license, while Phi 4 Reasoning uses MIT.

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

Grok-1.5

Proprietary

Closed source

Phi 4 Reasoning

MIT

Open weights

Release Timeline

When each model was launched

Grok-1.5 was released on 2024-03-28, while Phi 4 Reasoning was released on 2025-04-30.

Phi 4 Reasoning is 13 months newer than Grok-1.5.

Grok-1.5

Mar 28, 2024

2.2 years ago

Phi 4 Reasoning

Apr 30, 2025

1.1 years ago

1.1yr newer

Knowledge Cutoff

When training data ends

Phi 4 Reasoning has a documented knowledge cutoff of 2025-03-01, while Grok-1.5's cutoff date is not specified.

We can confirm Phi 4 Reasoning's training data extends to 2025-03-01, but cannot make a direct comparison without Grok-1.5's cutoff date.

Grok-1.5

—

Phi 4 Reasoning

Mar 2025

Outputs Comparison

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Key Takeaways

xAI

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

Microsoft
Has open weights
Higher GPQA score (65.8% vs 35.9%)
Higher MMLU-Pro score (74.3% vs 51.0%)

Detailed Comparison

AI Model Comparison Table
Feature
xAI
Grok-1.5
Microsoft
Phi 4 Reasoning

FAQ

Common questions about Grok-1.5 vs Phi 4 Reasoning.

Which is better, Grok-1.5 or Phi 4 Reasoning?

Phi 4 Reasoning significantly outperforms across most benchmarks. Grok-1.5 is made by xAI and Phi 4 Reasoning is made by Microsoft. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Grok-1.5 compare to Phi 4 Reasoning in benchmarks?

Grok-1.5 scores GSM8k: 90.0%, DocVQA: 85.6%, MMLU: 81.3%, HumanEval: 74.1%, MMMU: 53.6%. Phi 4 Reasoning scores FlenQA: 97.7%, HumanEval+: 92.9%, IFEval: 83.4%, OmniMath: 76.6%, AIME 2024: 75.3%.

What are the main differences between Grok-1.5 and Phi 4 Reasoning?

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

Who makes Grok-1.5 and Phi 4 Reasoning?

Grok-1.5 is developed by xAI and Phi 4 Reasoning is developed by Microsoft.

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