Claude Sonnet 3.6 (2022-10-22) vs xAI: Grok 4 Fast (free)
Compare Claude Sonnet 3.6 (2022-10-22) by Anthropic against xAI: Grok 4 Fast (free) by xAI, context windows of 200K vs 2.0M, tested across 35 shared challenges. Updated April 2026.
Which is better, Claude Sonnet 3.6 (2022-10-22) or xAI: Grok 4 Fast (free)?
Claude Sonnet 3.6 (2022-10-22) and xAI: Grok 4 Fast (free) are both competitive models. Claude Sonnet 3.6 (2022-10-22) costs $3/M input tokens vs $0/M for xAI: Grok 4 Fast (free). Context windows: 200K vs 2000K tokens. Compare their real outputs side by side below.
Key Differences Between Claude Sonnet 3.6 (2022-10-22) and xAI: Grok 4 Fast (free)
Claude Sonnet 3.6 (2022-10-22) is made by anthropic while xAI: Grok 4 Fast (free) is from xai. Claude Sonnet 3.6 (2022-10-22) has a 200K token context window compared to xAI: Grok 4 Fast (free)'s 2000K. On pricing, Claude Sonnet 3.6 (2022-10-22) costs $3/M input tokens vs $0/M for xAI: Grok 4 Fast (free).
No community votes yet. On paper, xAI: Grok 4 Fast (free) has the edge — newer, bigger context window.
Style Comparison
xAI: Grok 4 Fast (free) uses 28.1x more headings
vs
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178 models fingerprinted across 32 writing dimensions. Free research.
185x
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We read every word. 250 models. 2.14 million words. This is what we found.
