Claude Opus 4 vs Grok 3 Thinking

Compare Claude Opus 4 by Anthropic against Grok 3 Thinking by xAI, context windows of 200K vs 128K, tested across 7 shared challenges. Updated April 2026.

Which is better, Claude Opus 4 or Grok 3 Thinking?

Claude Opus 4 and Grok 3 Thinking are both competitive models. Context windows: 200K vs 128K tokens. Compare their real outputs side by side below.

Key Differences Between Claude Opus 4 and Grok 3 Thinking

Claude Opus 4 is made by anthropic while Grok 3 Thinking is from xai. Claude Opus 4 has a 200K token context window compared to Grok 3 Thinking's 128K.

Our Verdict
Claude Opus 4
Claude Opus 4
Grok 3 Thinking
Grok 3 ThinkingRunner-up

No community votes yet. On paper, Claude Opus 4 has the edge — newer, bigger context window.

Too close to call
Writing DNA

Style Comparison

Similarity
97%

Claude Opus 4 uses 11.2x more emoji

Claude Opus 4
Grok 3 Thinking
64%Vocabulary46%
62wSentence Length19w
0.52Hedging1.11
4.4Bold3.3
9.1Lists2.6
0.11Emoji0.00
1.87Headings0.64
0.27Transitions0.25
Based on 16 + 6 text responses
vs

Ask them anything yourself

Claude Opus 4Grok 3 Thinking

279 AI models invented the same fake scientist.

We read every word. 250 models. 2.14 million words. This is what we found.

AI Hallucination Index 2026
Free preview13 of 58 slides
FAQ

Common questions