Claude Opus 4 vs xAI: Grok 4 Fast (free)
Compare Claude Opus 4 by Anthropic against xAI: Grok 4 Fast (free) by xAI, context windows of 200K vs 2.0M, tested across 34 shared challenges. Updated May 2026.
Which is better, Claude Opus 4 or xAI: Grok 4 Fast (free)?
Claude Opus 4 and xAI: Grok 4 Fast (free) are both competitive models. Claude Opus 4 costs $15/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 Opus 4 and xAI: Grok 4 Fast (free)
Claude Opus 4 is made by anthropic while xAI: Grok 4 Fast (free) is from xai. Claude Opus 4 has a 200K token context window compared to xAI: Grok 4 Fast (free)'s 2000K. On pricing, Claude Opus 4 costs $15/M input tokens vs $0/M for xAI: Grok 4 Fast (free).
Per 1M tokens
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
Style Comparison
Claude Opus 4 uses 11.2x more emoji
