Model Comparison

Grok-4 Heavy vs Phi-3.5-vision-instructWhich is better in 2026?

Comparing Grok-4 Heavy and Phi-3.5-vision-instruct across benchmarks, pricing, and capabilities.

Verdict: Grok-4 Heavy vs Phi-3.5-vision-instruct — which is better?

Grok-4 Heavy (by xAI) and Phi-3.5-vision-instruct (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.

Choose Grok-4 Heavy if…

  • you are already invested in the xAI ecosystem

Choose Phi-3.5-vision-instruct if…

  • you need open weights you can self-host or fine-tune
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Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Grok-4 Heavy and Phi-3.5-vision-instructdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Input Capabilities

Supported data types and modalities

Both Grok-4 Heavy and Phi-3.5-vision-instruct support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Grok-4 Heavy

Text
Images
Audio
Video

Phi-3.5-vision-instruct

Text
Images
Audio
Video

License

Usage and distribution terms

Grok-4 Heavy is licensed under a proprietary license, while Phi-3.5-vision-instruct uses MIT.

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

Grok-4 Heavy

Proprietary

Closed source

Phi-3.5-vision-instruct

MIT

Open weights

Release Timeline

When each model was launched

Phi-3.5-vision-instruct was released on 2024-08-23, while Grok-4 Heavy's release date is not specified.

We can confirm Phi-3.5-vision-instruct's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.

Grok-4 Heavy

—

Phi-3.5-vision-instruct

Aug 23, 2024

1.8 years ago

Knowledge Cutoff

When training data ends

Grok-4 Heavy has a documented knowledge cutoff of 2024-12-31, while Phi-3.5-vision-instruct's cutoff date is not specified.

We can confirm Grok-4 Heavy's training data extends to 2024-12-31, but cannot make a direct comparison without Phi-3.5-vision-instruct's cutoff date.

Grok-4 Heavy

Dec 2024

Phi-3.5-vision-instruct

—

Outputs Comparison

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Key Takeaways

xAI

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

Microsoft
Has open weights

Detailed Comparison

AI Model Comparison Table
Feature
xAI
Grok-4 Heavy
Microsoft
Phi-3.5-vision-instruct

FAQ

Common questions about Grok-4 Heavy vs Phi-3.5-vision-instruct.

Which is better, Grok-4 Heavy or Phi-3.5-vision-instruct?

Grok-4 Heavy (xAI) and Phi-3.5-vision-instruct (Microsoft) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Grok-4 Heavy compare to Phi-3.5-vision-instruct in benchmarks?

Grok-4 Heavy scores AIME 2025: 100.0%, HMMT25: 96.7%, GPQA: 88.4%, LiveCodeBench: 79.4%, USAMO25: 61.9%. Phi-3.5-vision-instruct scores ScienceQA: 91.3%, POPE: 86.1%, MMBench: 81.9%, ChartQA: 81.8%, AI2D: 78.1%.

What are the main differences between Grok-4 Heavy and Phi-3.5-vision-instruct?

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

Who makes Grok-4 Heavy and Phi-3.5-vision-instruct?

Grok-4 Heavy is developed by xAI and Phi-3.5-vision-instruct is developed by Microsoft.

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