Claude Opus 4.6 vs o3 Mini

Compare Claude Opus 4.6 by Anthropic against o3 Mini by OpenAI, context windows of 1.0M vs 64K, tested across 53 shared challenges. Updated April 2026.

Which is better, Claude Opus 4.6 or o3 Mini?

Claude Opus 4.6 and o3 Mini are both competitive models. Claude Opus 4.6 costs $5/M input tokens vs $1.1/M for o3 Mini. Context windows: 1000K vs 64K tokens. Compare their real outputs side by side below.

Key Differences Between Claude Opus 4.6 and o3 Mini

Claude Opus 4.6 is made by anthropic while o3 Mini is from openai. Claude Opus 4.6 has a 1000K token context window compared to o3 Mini's 64K. On pricing, Claude Opus 4.6 costs $5/M input tokens vs $1.1/M for o3 Mini.

Our Verdict
Claude Opus 4.6
Claude Opus 4.6
o3 Mini
o3 MiniRunner-up

No community votes yet. On paper, Claude Opus 4.6 has the edge — bigger model tier, newer, bigger context window.

o3 Mini is 5.7x cheaper per token — worth considering if cost matters.

Slight edge
Writing DNA

Style Comparison

Similarity
87%

Claude Opus 4.6 uses 20.7x more emoji

Claude Opus 4.6
o3 Mini
53%Vocabulary65%
35wSentence Length17w
0.68Hedging0.74
5.2Bold3.9
2.9Lists1.7
0.21Emoji0.00
1.34Headings0.47
0.03Transitions0.38
Based on 23 + 12 text responses
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Claude Opus 4.6o3 Mini

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
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