Phi-3 Mini Instruct 3.8B vs Gemini 3.1 Pro Preview: Which AI Model Is Better?

Updated March 26, 2026· Based on independent benchmark data

Quick Verdict

Gemini 3.1 Pro Preview leads in intelligence with a score of 57.2 vs 10.1. For speed, Gemini 3.1 Pro Preview wins at 113 tok/s vs 0 tok/s.

Head-to-Head Comparison

Metric	Phi-3 Mini Instruct 3.8B	Gemini 3.1 Pro Preview
Intelligence Score	10.1	57.2
Coding Score	3.0	55.5
Math Score	0.3	N/A
Speed (tok/s)	0 tok/s	113 tok/s
Latency (TTFT)	0.00s	23.84s
Input Price / 1M tokens	Free	$2.00
Output Price / 1M tokens	Free	$12
Context Window	N/A

Detailed Analysis

Intelligence & Quality

Gemini 3.1 Pro Preview outperforms Phi-3 Mini Instruct 3.8B on the intelligence index with a score of 57.2 compared to 10.1. For coding tasks, Gemini 3.1 Pro Preview has the edge with a coding score of 55.5 vs 3.0.

Speed & Latency

Gemini 3.1 Pro Preview generates output significantly faster at 113 tok/s compared to Phi-3 Mini Instruct 3.8B's 0 tok/s, making it Infinityx faster for streaming responses. Time to first token is 0.00s for Phi-3 Mini Instruct 3.8B vs 23.84s for Gemini 3.1 Pro Preview, which affects perceived responsiveness in interactive applications.

Pricing

Phi-3 Mini Instruct 3.8B is completely free, while Gemini 3.1 Pro Preview costs $2.00/1M input tokens and $12/1M output tokens.

Best Use Cases

Choose Gemini 3.1 Pro Preview when you need higher intelligence (57.2), stronger coding performance (55.5), faster output (113 tok/s).

Choose Phi-3 Mini Instruct 3.8B if:

✓You want lower latency (0.00s vs 23.84s TTFT)
✓You want zero cost (Free vs paid)

Choose Gemini 3.1 Pro Preview if:

✓You need higher intelligence (score: 57.2 vs 10.1)
✓You prioritize coding performance (score: 55.5 vs 3.0)
✓You need faster throughput (113 tok/s vs 0 tok/s)
✓You need image understanding (Supports image input)

Frequently Asked Questions

Is Phi-3 Mini Instruct 3.8B better than Gemini 3.1 Pro Preview for coding?

Gemini 3.1 Pro Preview scores higher on coding benchmarks (55.5 vs 3.0), making it the better choice for programming tasks.

Is Phi-3 Mini Instruct 3.8B faster than Gemini 3.1 Pro Preview?

Gemini 3.1 Pro Preview is faster, producing output at 113 tok/s compared to Phi-3 Mini Instruct 3.8B's 0 tok/s.

Can Phi-3 Mini Instruct 3.8B process images?

No, Phi-3 Mini Instruct 3.8B does not support image input. However, Gemini 3.1 Pro Preview does support images.

Should I use Phi-3 Mini Instruct 3.8B or Gemini 3.1 Pro Preview?

It depends on your priorities. Gemini 3.1 Pro Preview scores higher on intelligence (57.2), but Phi-3 Mini Instruct 3.8B may be better for specific use cases like cost savings or speed-critical applications.

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View Phi-3 Mini Instruct 3.8Bdetails →View Gemini 3.1 Pro Previewdetails →Full pricing comparison →

Data last synced: March 26, 2026