xAI: Grok 4 Fast (free) vs Llama 3.1 405B
Compare xAI: Grok 4 Fast (free) by xAI against Llama 3.1 405B by Meta AI, context windows of 2.0M vs 128K, tested across 7 shared challenges. Updated April 2026.
Which is better, xAI: Grok 4 Fast (free) or Llama 3.1 405B?
xAI: Grok 4 Fast (free) and Llama 3.1 405B are both competitive models. xAI: Grok 4 Fast (free) costs $0/M input tokens vs $2.7/M for Llama 3.1 405B. Context windows: 2000K vs 128K tokens. Compare their real outputs side by side below.
Key Differences Between xAI: Grok 4 Fast (free) and Llama 3.1 405B
xAI: Grok 4 Fast (free) is made by xai while Llama 3.1 405B is from meta. xAI: Grok 4 Fast (free) has a 2000K token context window compared to Llama 3.1 405B's 128K. On pricing, xAI: Grok 4 Fast (free) costs $0/M input tokens vs $2.7/M for 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.
Style Comparison
xAI: Grok 4 Fast (free) uses 138.0x more bold
vsAsk them anything yourself
Some models write identically. You are paying for the brand.
178 models fingerprinted across 32 writing dimensions. Free research.
185x
price gap between models that write identically
178
models
12
clone pairs
32
dimensions
279 AI models invented the same fake scientist.
We read every word. 250 models. 2.14 million words. This is what we found.
