Model Comparison

Grok Code Fast 1 vs Phi 4 Reasoning PlusWhich is better in 2026?

Comparing Grok Code Fast 1 and Phi 4 Reasoning Plus across benchmarks, pricing, and capabilities.

Verdict: Grok Code Fast 1 vs Phi 4 Reasoning Plus — which is better?

Grok Code Fast 1 (by xAI) and Phi 4 Reasoning Plus (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 Code Fast 1 if…

  • you want the most recent training data — it shipped Aug 2025

Choose Phi 4 Reasoning Plus 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 Code Fast 1 and Phi 4 Reasoning Plus don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Grok Code Fast 1 specifies input context (256,000 tokens). Only Grok Code Fast 1 specifies output context (10,000 tokens).

xAI
Grok Code Fast 1
Input256,000 tokens
Output10,000 tokens
Microsoft
Phi 4 Reasoning Plus
Input- tokens
Output- tokens
Mon Jun 08 2026 • llm-stats.com

License

Usage and distribution terms

Grok Code Fast 1 is licensed under a proprietary license, while Phi 4 Reasoning Plus uses MIT.

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

Grok Code Fast 1

Proprietary

Closed source

Phi 4 Reasoning Plus

MIT

Open weights

Release Timeline

When each model was launched

Grok Code Fast 1 was released on 2025-08-28, while Phi 4 Reasoning Plus was released on 2025-04-30.

Grok Code Fast 1 is 4 months newer than Phi 4 Reasoning Plus.

Grok Code Fast 1

Aug 28, 2025

9 months ago

4mo newer
Phi 4 Reasoning Plus

Apr 30, 2025

1.1 years ago

Knowledge Cutoff

When training data ends

Phi 4 Reasoning Plus has a documented knowledge cutoff of 2025-03-01, while Grok Code Fast 1's cutoff date is not specified.

We can confirm Phi 4 Reasoning Plus's training data extends to 2025-03-01, but cannot make a direct comparison without Grok Code Fast 1's cutoff date.

Grok Code Fast 1

—

Phi 4 Reasoning Plus

Mar 2025

Outputs Comparison

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Key Takeaways

xAI
Larger context window (256,000 tokens)
Microsoft
Has open weights

Detailed Comparison

AI Model Comparison Table
Feature
xAI
Grok Code Fast 1
Microsoft
Phi 4 Reasoning Plus

FAQ

Common questions about Grok Code Fast 1 vs Phi 4 Reasoning Plus.

Which is better, Grok Code Fast 1 or Phi 4 Reasoning Plus?

Grok Code Fast 1 (xAI) and Phi 4 Reasoning Plus (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 Code Fast 1 compare to Phi 4 Reasoning Plus in benchmarks?

Grok Code Fast 1 scores SWE-Bench Verified: 70.8%. Phi 4 Reasoning Plus scores FlenQA: 97.9%, HumanEval+: 92.3%, IFEval: 84.9%, OmniMath: 81.9%, AIME 2024: 81.3%.

What are the context window sizes for Grok Code Fast 1 and Phi 4 Reasoning Plus?

Grok Code Fast 1 supports 256K tokens and Phi 4 Reasoning Plus 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 Grok Code Fast 1 and Phi 4 Reasoning Plus?

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

Who makes Grok Code Fast 1 and Phi 4 Reasoning Plus?

Grok Code Fast 1 is developed by xAI and Phi 4 Reasoning Plus is developed by Microsoft.

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