Model Comparison

Grok-3 Mini vs Phi-3.5-mini-instructWhich is better in 2026?

Grok-3 Mini significantly outperforms across most benchmarks. Phi-3.5-mini-instruct is 3.5x cheaper per token.

Verdict: Grok-3 Mini vs Phi-3.5-mini-instruct — which is better?

Grok-3 Mini (by xAI) and Phi-3.5-mini-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.

Grok-3 Mini outperforms in 1 benchmarks (GPQA), while Phi-3.5-mini-instruct is better at 0 benchmarks. Grok-3 Mini significantly outperforms across most benchmarks.

On price, Phi-3.5-mini-instruct is roughly 3.5x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Choose Grok-3 Mini if…

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

Choose Phi-3.5-mini-instruct if…

  • cost matters — it's about 3.5x cheaper per token
  • you need open weights you can self-host or fine-tune

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Grok-3 Mini outperforms in 1 benchmarks (GPQA), while Phi-3.5-mini-instruct is better at 0 benchmarks.

Grok-3 Mini significantly outperforms across most benchmarks.

Mon Jul 27 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Phi-3.5-mini-instruct costs less

For input processing, Grok-3 Mini ($0.30/1M tokens) is 3.0x more expensive than Phi-3.5-mini-instruct ($0.10/1M tokens).

For output processing, Grok-3 Mini ($0.50/1M tokens) is 5.0x more expensive than Phi-3.5-mini-instruct ($0.10/1M tokens).

In conclusion, Grok-3 Mini is more expensive than Phi-3.5-mini-instruct.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Mon Jul 27 2026 • llm-stats.com
xAI
Grok-3 Mini
Input tokens$0.30
Output tokens$0.50
Best providerxAI
Microsoft
Phi-3.5-mini-instruct
Input tokens$0.10
Output tokens$0.10
Best providerAzure
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Both models have the same input context window of 128,000 tokens. Phi-3.5-mini-instruct can generate longer responses up to 128,000 tokens, while Grok-3 Mini is limited to 8,000 tokens.

xAI
Grok-3 Mini
Input128,000 tokens
Output8,000 tokens
Microsoft
Phi-3.5-mini-instruct
Input128,000 tokens
Output128,000 tokens
Mon Jul 27 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Grok-3 Mini supports multimodal inputs, whereas Phi-3.5-mini-instruct does not.

Grok-3 Mini can handle both text and other forms of data like images, making it suitable for multimodal applications.

Grok-3 Mini

Text
Images
Audio
Video

Phi-3.5-mini-instruct

Text
Images
Audio
Video

License

Usage and distribution terms

Grok-3 Mini is licensed under a proprietary license, while Phi-3.5-mini-instruct uses MIT.

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

Grok-3 Mini

Proprietary

Closed source

Phi-3.5-mini-instruct

MIT

Open weights

Release Timeline

When each model was launched

Grok-3 Mini was released on 2025-02-17, while Phi-3.5-mini-instruct was released on 2024-08-23.

Grok-3 Mini is 6 months newer than Phi-3.5-mini-instruct.

Grok-3 Mini

Feb 17, 2025

1.4 years ago

5mo newer
Phi-3.5-mini-instruct

Aug 23, 2024

1.9 years ago

Knowledge Cutoff

When training data ends

Grok-3 Mini has a documented knowledge cutoff of 2024-11-17, while Phi-3.5-mini-instruct's cutoff date is not specified.

We can confirm Grok-3 Mini's training data extends to 2024-11-17, but cannot make a direct comparison without Phi-3.5-mini-instruct's cutoff date.

Grok-3 Mini

Nov 2024

Phi-3.5-mini-instruct

—

Provider Availability

Grok-3 Mini is available from xAI. Phi-3.5-mini-instruct is available from Azure.

Grok-3 Mini

xai logo
xAI
Input Price:Input: $0.30/1MOutput Price:Output: $0.50/1M

Phi-3.5-mini-instruct

azure logo
Azure
Input Price:Input: $0.10/1MOutput Price:Output: $0.10/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

xAI
Supports multimodal inputs
Higher GPQA score (84.0% vs 30.4%)
Microsoft
Less expensive input tokens
Less expensive output tokens
Has open weights
xAIGrok-3 Mini
MicrosoftPhi-3.5-mini-instruct
Compare in Playground

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Grok-3 Mini and Phi-3.5-mini-instruct side-by-side, then vote on the output you prefer.

Grok-3 Mini
✓ Preferred
Phi-3.5-mini-instruct
Open in Playground
AI Model Comparison Table
Feature
xAI
Grok-3 Mini
Microsoft
Phi-3.5-mini-instruct

FAQ

Common questions about Grok-3 Mini vs Phi-3.5-mini-instruct.

Which is better, Grok-3 Mini or Phi-3.5-mini-instruct?

Grok-3 Mini significantly outperforms across most benchmarks. Grok-3 Mini is made by xAI and Phi-3.5-mini-instruct is made by Microsoft. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Grok-3 Mini compare to Phi-3.5-mini-instruct in benchmarks?

Grok-3 Mini scores AIME 2024: 95.8%, AIME 2025: 90.8%, GPQA: 84.0%, LiveCodeBench: 80.4%. Phi-3.5-mini-instruct scores GSM8k: 86.2%, ARC-C: 84.6%, RULER: 84.1%, PIQA: 81.0%, OpenBookQA: 79.2%.

Is Grok-3 Mini cheaper than Phi-3.5-mini-instruct?

Phi-3.5-mini-instruct is 3.0x cheaper for input tokens. Grok-3 Mini costs $0.30/M input and $0.50/M output via xai. Phi-3.5-mini-instruct costs $0.10/M input and $0.10/M output via azure.

What are the context window sizes for Grok-3 Mini and Phi-3.5-mini-instruct?

Grok-3 Mini supports 128K tokens and Phi-3.5-mini-instruct supports 128K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Grok-3 Mini and Phi-3.5-mini-instruct?

Key differences include input pricing ($0.30 vs $0.10/M), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok-3 Mini and Phi-3.5-mini-instruct?

Grok-3 Mini is developed by xAI and Phi-3.5-mini-instruct is developed by Microsoft.

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