GPT-4o (Omni) vs Llama 3.1 405B

Compare GPT-4o (Omni) by OpenAI against Llama 3.1 405B by Meta AI, context windows of 128K vs 128K, tested across 6 shared challenges. Updated March 2026.

Which is better, GPT-4o (Omni) or Llama 3.1 405B?

GPT-4o (Omni) and Llama 3.1 405B are both competitive models. GPT-4o (Omni) costs $2.5/M input tokens vs $2.7/M for Llama 3.1 405B. Context windows: 128K vs 128K tokens. Compare their real outputs side by side below.

Key Differences Between GPT-4o (Omni) and Llama 3.1 405B

GPT-4o (Omni) is made by openai while Llama 3.1 405B is from meta. GPT-4o (Omni) has a 128K token context window compared to Llama 3.1 405B's 128K. On pricing, GPT-4o (Omni) costs $2.5/M input tokens vs $2.7/M for Llama 3.1 405B.

Our Verdict
GPT-4o (Omni)
GPT-4o (Omni)
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.

Llama 3.1 405B is 3.2x cheaper per token — worth considering if cost matters.

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