OpenAI o4-mini vs Llama 3.1 405B

Compare OpenAI o4-mini by OpenAI against Llama 3.1 405B by Meta AI, tested across 6 shared challenges. Updated March 2026.

Which is better, OpenAI o4-mini or Llama 3.1 405B?

OpenAI o4-mini and Llama 3.1 405B are both competitive models. OpenAI o4-mini costs $1.1/M input tokens vs $2.7/M for Llama 3.1 405B. Compare their real outputs side by side below.

Key Differences Between OpenAI o4-mini and Llama 3.1 405B

OpenAI o4-mini is made by openai while Llama 3.1 405B is from meta. On pricing, OpenAI o4-mini costs $1.1/M input tokens vs $2.7/M for Llama 3.1 405B.

Our Verdict
OpenAI o4-mini
OpenAI o4-mini
Llama 3.1 405B
Llama 3.1 405B

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call
Writing DNA

Style Comparison

Similarity
81%

Llama 3.1 405B uses 2.9x more emoji

OpenAI o4-mini
Llama 3.1 405B
73%Vocabulary56%
15wSentence Length15w
0.18Hedging0.41
0.0Bold0.0
2.1Lists1.9
0.00Emoji0.03
0.00Headings0.00
0.02Transitions0.16
Based on 10 + 5 text responses
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OpenAI o4-miniLlama 3.1 405B
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