Compare/Phi-3 Mini Instruct 3.8B vs o3

Phi-3 Mini Instruct 3.8Bvso3

Side-by-side comparison of pricing, 12 benchmarks, and generation speed.

Microsoft

Phi-3 Mini Instruct 3.8B

Input
$0/M
Output
$0/M
Speed
TTFT
OpenAI

o3

Input
$2/M
Output
$8/M
Speed
125 tok/s
TTFT
6.65s

Winner by Category

Cheaper
Phi-3 Mini Instruct 3.8B
Faster (tok/s)
o3
Lower Latency
Phi-3 Mini Instruct 3.8B
Benchmarks (0-11)
o3

Pricing Comparison

MetricPhi-3 Mini Instruct 3.8Bo3
Input ($/M tokens)$0$2
Output ($/M tokens)$0$8
Cost for 1M input + 100K output tokens:
Phi-3 Mini Instruct 3.8B$0.00
o3$2.80

Speed Comparison

Output Speed (tokens/s) — higher is better
Phi-3 Mini Instruct 3.8B
o3
125 tok/s
Time to First Token (seconds) — lower is better
Phi-3 Mini Instruct 3.8B
o3
6.65s

Benchmark Comparison

Data from Artificial Analysis API — 12 benchmarks

Intelligence Index
4.630.4
Coding Index
Math Index
0.388.3
GPQA Diamond
31.9%82.7%
MMLU-Pro
43.5%85.3%
LiveCodeBench
11.6%80.8%
AIME 2025
0.3%88.3%
MATH-500
45.7%99.2%
Humanity's Last Exam
4.4%20.0%
SciCode
9.0%41.0%
IFBench
23.9%71.4%
TerminalBench
0.0%37.1%
Phi-3 Mini Instruct 3.8B0 wins
11 winso3

Frequently Asked Questions

Which is cheaper, Phi-3 Mini Instruct 3.8B or o3?

Phi-3 Mini Instruct 3.8B is cheaper overall. Its blended price (3:1 input/output ratio) is $0.00/M tokens vs $3.50/M for o3.

Which model performs better on benchmarks?

o3 wins 11 out of 12 benchmarks compared to 0 for Phi-3 Mini Instruct 3.8B. See the detailed benchmark chart above for per-category results.

Which is faster for real-time applications?

o3 generates tokens faster at 125 tok/s vs 0 tok/s. Phi-3 Mini Instruct 3.8B also has lower time-to-first-token (0.00s vs 6.65s).

When should I use Phi-3 Mini Instruct 3.8B vs o3?

Choose based on your priorities: Phi-3 Mini Instruct 3.8B for lower cost, o3 for stronger benchmark performance, and o3 for faster generation. For latency-sensitive apps, check the TTFT comparison above.