xAI: Grok 4 Fast (free) vs Inception: Mercury 2
Compare xAI: Grok 4 Fast (free) by xAI against Inception: Mercury 2 by Inception, context windows of 2.0M vs 128K, tested across 34 shared challenges. Updated April 2026.
Which is better, xAI: Grok 4 Fast (free) or Inception: Mercury 2?
xAI: Grok 4 Fast (free) and Inception: Mercury 2 are both competitive models. xAI: Grok 4 Fast (free) costs $0/M input tokens vs $0.25/M for Inception: Mercury 2. Context windows: 2000K vs 128K tokens. Compare their real outputs side by side below.
Key Differences Between xAI: Grok 4 Fast (free) and Inception: Mercury 2
xAI: Grok 4 Fast (free) is made by xai while Inception: Mercury 2 is from inception. xAI: Grok 4 Fast (free) has a 2000K token context window compared to Inception: Mercury 2's 128K. On pricing, xAI: Grok 4 Fast (free) costs $0/M input tokens vs $0.25/M for Inception: Mercury 2.
No community votes yet. On paper, xAI: Grok 4 Fast (free) has the edge — bigger model tier, bigger context window, major provider backing.
Style Comparison
Inception: Mercury 2 uses 8.2x more emoji
vsAsk them anything yourself
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178 models fingerprinted across 32 writing dimensions. Free research.
185x
price gap between models that write identically
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clone pairs
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279 AI models invented the same fake scientist.
We read every word. 250 models. 2.14 million words. This is what we found.
