Llama 3.1 405B vs Grok 3

Compare Llama 3.1 405B by Meta AI against Grok 3 by xAI, context windows of 128K vs 128K, tested across 7 shared challenges. Updated April 2026.

Which is better, Llama 3.1 405B or Grok 3?

Llama 3.1 405B and Grok 3 are both competitive models. Context windows: 128K vs 128K tokens. Compare their real outputs side by side below.

Key Differences Between Llama 3.1 405B and Grok 3

Llama 3.1 405B is made by meta while Grok 3 is from xai. Llama 3.1 405B has a 128K token context window compared to Grok 3's 128K.

Our Verdict
Llama 3.1 405B
Llama 3.1 405B
Grok 3
Grok 3

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
86%

Grok 3 uses 246.4x more bold

Llama 3.1 405B
Grok 3
56%Vocabulary49%
15wSentence Length18w
0.41Hedging0.94
0.0Bold2.5
1.9Lists3.0
0.03Emoji0.04
0.00Headings0.65
0.16Transitions0.08
Based on 5 + 17 text responses
vs

Ask them anything yourself

Llama 3.1 405BGrok 3

279 AI models invented the same fake scientist.

We read every word. 250 models. 2.14 million words. This is what we found.

AI Hallucination Index 2026
Free preview13 of 58 slides
FAQ

Common questions