Grok 3 Thinking vs Claude Opus 4

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

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

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

Key Differences Between Grok 3 Thinking and Claude Opus 4

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

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

Grok 3 Thinking
Claude Opus 4
46%Vocabulary64%
19wSentence Length62w
1.11Hedging0.52
3.3Bold4.4
2.6Lists9.1
0.00Emoji0.11
0.64Headings1.87
0.25Transitions0.27
Based on 6 + 16 text responses
vs

Ask them anything yourself

Grok 3 ThinkingClaude Opus 4

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

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